Sketchbook study of the Common hop

Overview of Hop plants

Hops are members of the Cannabaceae family, and are native to the Northern hemisphere.  There are three species of hop, and any number of varieties of the Common hop.  This is due to the plant’s history in brewing beer; different varieties of common hop create different flavours.

Hops are climbers, supporting their spiralling growth on whatever comes to hand (well, to tendril).

Common hop tendril

Both plants get big, with 6 m in height being the average.  Japanese hop can grow up to 10 m in one growing season.  This depends on how high the substrate or support they’re twining around is.  If it’s a telegraph pole or tree, then the plant can get close to its maximum height.

Scale illustration of Japanese hop with grown man of 180 cm

Stems

Both these species are vigorous climbers, aided by their spiny twining stems.  They are perennial climbers, sometimes referred to as bines.

Their stems are non-woody and have four sides, with backward pointing prickles that help the plants to climb in a clockwise direction.  (Interestingly, bines which grow anticlockwise, such as Virginia creeper, use suckers and tendrils rather than spines.)

However, the Japanese hop has hairs on its stem alongside the spines; in Common hop these are absent.

Japanese hop vs Common hop stems

Shoots grow at a prodigious rate, the Common hop can grow 20 – 50 cm a week in summer.  These shoots are edible, and a tasty edition to salads or eaten as a green vegetable.

Japanese hop seedling

They have lobed leaves which grow in opposite pairs, and as male and female flowers are borne on different plants, they’re dioecious.

Leaves

Japanese and Common hop have lobed leaves; Common hop leaves are a little smaller than those of the Japanese hop, being 5 – 13 cm instead of 10 – 15 cm.  They’re both rough to the touch.  Common hop leaves are more or less glabrous above and have downy hair that follows the lines of the veins below.  They also have little yellow glands on the underside.  Japanese hop leaves are described as finely hairy, with minute hooked bristles on the upper and lower leaf surface.  The glands on the underside of their leaves are white.

Both species have lobes.  Common hop have three to five lobes, although most have three.  Japanese hop leaves have three to seven lobes.  Most leaves have five, but leaves toward the top of the plant may have only three.

Japanese hop leaf vs Common hop leaf

The teeth on the margins of Common hop are blunt, while those of Japanese hop are pointier.

Although the leaf stalk or petiole is long in both species, it’s generally longer in the Japanese hop.  In fact, it’s longer than the leaf blade itself.  Common hop stipules are far shorter than the leaf blade.  Some sources suggest that the stipule at the petiole base can be used to tell the two species apart.  Common hop stipules are smaller, hairless, and drop off pretty soon.  They split before being shed.  Those of the Japanese hop curve downward, are triangular and persistent, and are covered in hairs.

Male flowers

Being dioceious, male and female flowers are borne on different plants.  As it’s the female flowers of the Common hop that produce what we consider “hops”, they’re the plants that have been encouraged over the years.  In fact, male Common hops were prohibited in Ireland under the Noxious weeds act of 1965.

Male flowers of both species look similar and are borne in loose-branching clusters.  Those of Common hop are borne on drooping branches with clusters of 20 – 100 flowers, while those of the Japanese hop are said to be held erect.  Again, it’s a cluster of 20 – 100 flowers.  Both have five spreading sepals, and five stamens.  These are pale yellow with darker yellow glands in the case of Common hop. The sepals of the Japanese hop are hairy, those of the Common hop are not.

Male flower of the Japanese hop

Female flowers

Female plants can be propagated with vegetative reproduction.

Male hops were discouraged as if the hop plant produced seeds, the fatty acids within the seeds could alter the flavour of the hops and thus distort the brewing process.

Japanese hop seed

Female flowers are pistillate, having no stamens, with 2 thread-like styles.  They’re borne in cone-like spikes which appear at the top pf branches that grow from the leaf axils.  There are a few to several flowers per cluster.  The female flowers lack petals, and each is surrounded by a green bract.

Female flower of the Common hop (without basal bracts)

Female Common hop flowers have 10 – 50 pairs of flowers per cluster, and each pair of flowers has a glabrous pale green bract at its base, with a blunt tip and yellow glands at its base.  The bracts of Japanese hop are more pointed, and covered in sparse white hairs.

Maturing female flower of the Common hop

Fruit

The fruit of the Common hop is the part used in brewing beer.  They’re called strobilus (plural strobili) meaning cone.  If you look at one next to a pine cone, this makes sense.

Common hop strobili are pale green, papery, and up to 3cm in length.  They are hairless and each bract is blunt.

Simplifies illustration on Common hop strobili

Japanese hop strobili are a darker, bright green.  They’re hairy, with most hairs at the base of each bract.  The bract tips are acuminate.

When seen together, the difference between the two species is clear.

Japanese female cone or strobili vs Common hop strobili

I mentioned the number of seeds per bract; as stated earlier, hops used in the brewing industry are barren.

Conclusion

My main problem researching the hops is not the difference between these two species.  That’s easy enough; the leaves and stems are very different, as are the strobili.  No.  My main challenge was getting my head round the structure of the monoecious hop inflorescence, and understanding what structures were present (or were not) in each.

There were many rabbit-holes that I fell down whilst researching this blog.  Did you know that until 1915, in Finland, peasants had to provide Common hop as part of their annual tax bill?  Or that Common hop plants which germinated 8,000 years ago still have ancestors twining around alder trees?  (Both of these facts are from the excellent Natures Gate site).

The varieties of Common hop, some lost and some saved from the brink of extinction, are numerous and fascinating.

The uses of hop are numerous, not only for weaving tough fabric and brewing beer; but for making dye, medicine, and for their anti-bacterial properties.  Hops have been used to treat anxiety and sleep disorder, and to froth up beer, as well as to flavour it.

I love how one plant can open a hundred doorways.

Pencil rough of the Japanese hop

Resources

Lots of great online resources helped me here.  The Midwest Invasive Species Network, Minnisota Wildflowers has excellent pages on Common and Japanese hop, The Center for Invasive Species and Ecosystem Health has lots of images for Japanese and Common hop; and there’s a rather lovely blog about the hops growing at the Met museum’s Cloister gardens.

These original illustrations are mostly available to buy.  Have a browse in the Original unframed sketchbook illustrations and Original unframed plant illustrations section of my website, using the search facility.

The post Comparing Common and Japanese Hops appeared first on Lizzie Harper.

Overview of Canadian Goldenrod Solidago canadensis and Early Goldenrod Solidago gigantea

The focus of the illustration is the Canadian goldenrod.

Most Goldenrods are native to the Americas.  However, there’s one species native to Europe (Woundwort Solidago virgaurea).

Both Canadian and Early Goldenrod Solidago gigantea grow wild in Scandanavia.  Garden escapes were noted as early as 1910.  Although it’s an invasive, and can be a nuisance, Goldenrod does bring benefits.  It’s extremely good for pollinators, and attracts lots of butterflies.  As it flowers late in the year, it provides a welcome food supply for insects about to overwinter.  (To make your garden wildlife friendly, check out the Save the Bees guest blog.)

Goldenrod plants grows on waste ground.  Sometimes they form dense clumps along railway tracks and roads.

Canadian goldenrod flowers August to October.  However, Early goldenrod blooms from July.

Goldenrod is a member of the daisy or Compositae family.  As with other members of this large and successful group, its flowers are made of disc and ray florets.  For more on this, please check out my blog.

Canadian goldenrod

The Canadian goldenrod plant is tall, 30 – 150 cm.  Densely leafy, it’s covered in downy hairs which are more obvious toward the top of the plant.  Giant or Early goldenrod is glabrous.  It’s a larger plant, up to 250 cm high.  Often, its stems are blueish towards the base.

The plant reproduces by means of far-reaching rhizomes, and with seeds.  These have fluffy pappas which catch the wind and spread the seed widely.

Leaves

Canadian goldenrod leaves are alternate and toothed.  About 2/3 of the way down the leaf edge the teeth give over to leave a smooth margin toward the base.  As with the rest of the plant, they’re hairy.

Early goldenrod has teeth which carry round the entire margin of the leaf.  Any hairs follow the lines of the veins.

Early goldenrod and Canadian goldenrod leaf comparison

Canadian goldenrod leaves have three veins; while the Early goldenrod sports five.

Stems

The stem of Canadian goldenrod is covered in downy hairs.  It is often flushed red.  Stems of the Early goldenrod are hairless, and may be flushed red or a more intense purple.

Early goldenrod stem compared to Canadian goldenrod stem

Flowering spike

The flowering spike is similar in both species.  It carries lots of golden flowers, and tends to curve a little.

Canadian goldenrod with comparative notes on Early goldenrod

Individual flowers

Each individual flower is composed of ray florets around the outside edge, and disc florets within.  Both have 5 yellow stamen.  There are some noticeable differences between these golden blooms.

The Canadian goldenrod is 5 – 6 mm across and has 10 – 17 short ray florets per flower.  Tips of each are blunt, and rounded.  In shape, the capitulum is domed.  Flowers are carried in wide, pyramid-like panicles.

With the Early goldenrod, there are fewer ray florets per flower, 7 – 12 of them.  Each flower is a smaller 2 – 3 mm.  Ligules of the ray florets are significantly longer, with more pointed tips.  Another differnce is the capitulum, which are are more pyramidal than in Canadian goldenrod.  The flowering branches tend to be straighter and held more erect.  Branches may be slightly hairy towards their top.

Early goldenrod flowers compared to Canadian goldenrod flowers

Seeds

These are similar in both species, but the Early goldenrod has longer pappas.  Canadian goldenrod seeds have a slightly downy tip.

Currently in Sweden and Finland the cold weather comes before the Early goldenrod sets seed.  As global warming leads to longer summers this plant could become an increasingly problematic invasive in Scandinavia.

Early goldenrod cypsela vs that of the Canadian goldenrod

Resources

Naturespot has helpful and concise information on the Canadian goldenrod and on the Early goldenrod.  Yet again, Naturegate has great pages for both Canadian and Giant goldenrod.

This original sketchbook illustration is available for sale along with many other original illustrations.  Why not have a browse at Original Illustrations for sale?

The post Comparing Goldenrod Species appeared first on Lizzie Harper.

This chart of flowers of walks and the wayside shows a wide variety of different flower shapes.  Here’s how we go about naming some of them…

First, we have to accept the amazing variety of form.  So what causes this variety?  Flower shape depends on how the segments of the perianth (sepals and petals) are arranged, and what shape they are.

I need to give a caveat before setting out.  There is an enormous amount of variation between definitions of flower shape.  Different botanists use different terms.  They may choose from only a handful of shape definitions, or from an enormous selection.  Many of the definitions seem to be almost inter-changeable.  I’ve done my best to try and untangle some of these contradictions, but please do get in touch in the comments section if you spot glaring errors!

Flower symmetry

The first thing to consider is the axis of symmetry.  Does the flower have bilateral symmetry?  Does it have a clear top and bottom, with two similar sides?  If you cut it in half would both sides be mirror images?  This is known as Zygomorphic symmetry.  Violets show this form.

If a flower is radially symmetrical, then you can cut it in half anywhere and the halves will be identical.  It’s a little like the idea of cutting a cake into two equal parts.  This is referred to as being Actinomorphic.  Most flowers show this symmetry; cranesbills and daisies, forget-me-nots, roses, and borage flowers.

For more on flower symetry, check out the blog from Orbis Environment.

Early dog violet Viola reichenbachiana with several flowers showing Zygomorphic symmetry

Dog rose Rosa canis showing Actinomorphic symmetry

Flower shapes: How to approach these terms

There’s no pretty way to do this, except by working through each botanical term one by one. Brace yourselves, there are about eighteen of these terms to get through!

Cyanthiform

First up is Cyanthiform.  A Cyanthiform flower is shaped like a cup of a bowl.  It has radial or actinomorphic symmetry.  The petals curve upwards, forming the bowl shape.

Buttercups have Cyanthiform flowers.

Cruciform

Cruciform flowers have four petals, and are cross-like.  They have Actinomorphic symmetry.  Many flowers have this form, although often they’re little white numbers that we might overlook.

the Bedstraw family all have little white Cruciform flowers.

Crateriform

Crateriform flowers are similar in shape to Cyanthiform ones.  To be honest, I couldn’t find any online reference which made any difference between the two clear.  Perhaps it relates to petal number?  Or maybe the terms are inter-changable?

In any case, Crateriform flowers are bowl shaped, rather like a saucer.  They show actinomorphic symmetry.

A good example of a Crateriform flower is the poppy.  In this case, I’m using the California poppy.

California poppy Eschscholzia californica

Coronate

Coronate flowers are easy, it’s rather a relief.  Any flower which is crown-like, and looks like a daffodil is coronate.  I can’t think of many flowers that do take on this form, except for the masses of variety of Narcissus and our spring daffs.

Wild daffodil Narcissus pseudonarcissus

Campanulate

Another easy one.  Campanulate means bell-shaped, or bell-like.  In fact, all the bell flowers are campanulate.  That’s why their family is called the Campanulaceae!  Although they have a longer corolla tube or throat, they’re still radially symmetrical.  Campanulate flowers are actinomorphic.  A good example of a campanulate flower is the harebell

Harebell Campanula rotundifolia

Calceolate

Calceolate flowers are very distinctive, and it’s an uncommon shape.  The term translates from the latin as shoe-like, or slipper-like.  The only examples of calceolate flowers I can think of are the slipper orchids, none of which I’ve illustrated.  Calceolate flowers are bilaterally symmetrical, so they are zygomorphic.

Urceolate

Urceolate flowers are like little urns or vessels, facing down.  They have neat petals at the top and a rounded corolla tube.  They’re actinomorphic.  The heather are a great example of urceolate flowers, especially the bell heather.  Another good example is the blueberry, and the Strawberry tree.

Tubulate

Another self-explanatory term.  Tubulate flowers are like little tubes.  Their petals don’t splay out at the top of the tube.  An example of a tubulate bloom is the Cigar flower.  You may not be surprised to hear I’ve not illustrated this species.

Stellate

Stellate flowers are interesting.  They’re star shaped, and radially symmetrical.  But the most interesting thing about these actinomorphic blooms is that they consist of tepals, not petals.  “What”, I hear you cry “is a tepal!?”  Some flowers have sepals and petals which are so similar as to be almost identical.  In many flowers, the sepals are very different from the flowers, and mostly green.

With stellate flowers such as lilies, the onion family, and tulips this is not so.  The sepals are as brightly coloured as the petals, and are often indistinguishable.  You can only tell them apart by seeing where they attach to the centre of the flower.  It’s easier to refer to both the sepals and the petals as tepals.

Three cornered leek Allium triquetrum

Salverform

Salverform flowers are shaped like a long tube, and have a flattened disc of petals at the top.  There’s not much curving of the petals, so the face of a salverform flower is pretty flat.  Plumbago is the example given by many of my references, but I’ve not illustrated that.

Salverform flowers are antinomorphic, posessing radial symmetry.

Saccate

Yet another of these flower shapes that I’ve not illustrated.  Saccate flowers have their basal coralla area extended and swollen, like a bag.  The corolla is fused into a tube.  The distinctive bulge is always on the lower side of the flower.

Saccate flowers are zygomorphic, or bilaterally symmetrical.  Unfortunately, the only example I could find was the Nemathus.  Alas, it;s another plant I haven’t yet illustrated.

Rotate

Rotate flowers are very common.  However, their distinctive characteristic is that the petals aren’t fused together, or if fused it’s a very short tube. No corolla tubes or fusing.  Clearly, rotate flowers are actinomorphic. Tomato  flowers are rotate.

I’m going to admit to a background level of confusion here.  Different sources have different opinions on what species show a rotate form.  I’m erring on the side of caution, and leaving the tomato as our sample flower.  Unfortunately, it’s another species I’ve not illustrated!

Papilionaceaous

We’re back onto safer ground with a papilionaceous flower form.  These are said to resemble butterflies, hence the name.  They’re zygomorphic as they show bilateral symmetry.  A papilionaceaous flower is easy to spot.  All the vetches and the pea family show this flowering shape.

Bitter vetch Lathyrus linifolius

Ligulate

It’s another easy one to explain.  A ligule is the strap-like petal found on the ray florets of the Compositae.  So a plant having a ligulate flower form is one that resembles a daisy.  Outer ray-like petals are the order of the day.  Ligulate flowers are actinomorphic.

The clearest example of a ligulate flower form is the daisy.

African daisy Gerbera

Labiate and Bilabiate

Labiate flowers have lips, or are lipped.  The flowers look like a throat with an upper an lower lip, resembling a mouth  They tend to have long, fused corolla tubes with an enlarged lower lip.  Labiate flowers show bilateral or zygomorphic symmetry.

Bilabiate flowers have two lips.  These are often fused at their bases.  All the mint family (Lamiaceae) have bilabiate flowers.

There’s rather a good link if you want to know more about labiate flower form, from Orbis consulting.

Catnip Nepeta cataria

Galeate

Galeate flowers are hooded, or helmeted.  Like the labiate flower forms, they have a clear lower lip.  The main distinction is the obvious hood over the top of the flower.  This is called a galea.  Think of a dead nettle or monkshood (the clue’s in the name!).

Lousewort also have a galeate form.

Lousewort Pedicularis sylvatica

In my illustration the hood is less pronounced than it might be.

Funnelform

Another easy one to end with.  Funnelform flowers look a whole lot like a funnel.  The flower shape widens slowly from the base, into a trumpet or funnel shape.  Like many of the other flower shapes, funnelform blooms are actinomorphic.

The most obvious examples of funnelform flowers are the Convulvulus, like the morning glory below.

Morning glory Ipomoea purpurea

Flower shapes: An overview and conclusion

Now we’ve gone through each shape one by one, here they all all together on one sheet:

My main references for this blog were The Cambridge Illustrated Glossary of Botanical Terms by Michael Hickey and Clive King, and Kew Plant Glossary by Henk Beentje.

There are loads of websites on this topic, all with slightly different terms.  A good one is the Flowers on India site, and the Seed site.  It can be useful to have an online dictionary of botanical terms to refer to, the Wikipedia dictionary of botanical terms is pretty exhaustive, and the Florabase glossary is a good resource.

The main thing to bear in mind, as your head spins with the variety of flower shapes, is what it’s all for.  The diversity and beauty of these structures comes down to pollination, and attracting pollinators to a flower.  As Candace Galan states in the article “Why do Flowers vary? “Nearly all botanists give animal pollinators credit for the vast smorgasbord of flower shapes and sizes observed in nature.”  However, as she point out, other environmental factors are also involved, as are a plant’s enemies and the costs of producing these amazing flowers.

For more of my blogs on plant morphology and botanical terms, click the link.

The post Flower Shapes: Terminology appeared first on Lizzie Harper.

(We should also mention the rushes and sedges.  These are also monocots.  For a beginners guide to sedges click here, for a beginners guide to rushes follow this link.)

Drawing a plant is one of the best ways to begin to understand it.  I hope this crash course in grass anatomy will help.

Anatomy of Grass:   Overview of the Plant

Grasses have long leaves or blades, straight thin roots, a rounded (often hollow) stem (or culm), and a flowering spike.  Lots of people may not realise that the top region of a grass plant happens to be the plant’s flowers and seeds.  It becomes obvious when you think about a grass like wheat, but other species might fall under the radar.

Bread wheat Triticum aestivum

The culm of a grass has “knees”, these are known as nodes.  These nodes might be at a bend in the culm, or just on a straight run of the stem.  The culm tends to be swollen at the nodes.  They may be hairy or smooth, depending on species.  This bending at the nodes is known as genticulate growth.  Some people confuse grasses with sedges and rushes; remember that grasses are the only one of these groups which can “bend at the knees”.

The space between these nodes is called the internode.  Its length can help differentiate between species of grass.

Blades (leaves) of grass tend to be flat and linear.  They are rranged alternatively up the culm, and have parallel and unbranching veins.  Blades can be broad, or needle like.  In some species they roll in on themselves to make bristle-like leaves.  Noting if they are hairy or smooth helps determine the species.

The blades of grass grow up the culm like a tube, then grow outward.  This encircling or tubular covering is known as a sheath. Sheaths may cling tight to the culm.  They may be loose and inflated.  This is yet another thing to look out for if you’re trying to i.d. a grass plant.

Overview of the anatomy of a grass (Meadow oat grass Avenula pratensis)

Grass Ligules

Ligules are little flaps of membranous tissue that form at the top of the sheath and the base of the leaf blade.  They are very cool as their shape varies a great deal from species to species.  In many cases they’re tiny, so a hand lens might be handy if you’re going to take a closer look.  Some ligules are pointed, some are rough edged, some very thin, some broad and easy to spot.  Some species have no ligule, or have a ligule which is reduced to a ring of hairs.

Sometimes the edges of the leaf blade cling to the culm and surround the ligule (as in the second illustration below); these structures are called auricles.

Ligule variety in different species of grasses

Inflorescence variety in Grasses

The flowering part of a grass plant is called the panicle, flowering spike, inflorescence or flower-head (many of these terms also apply to other families of plant, and botanists use them somewhat differently at times, which can be confusing). These flowering heads consists of lots of tiny grass flowers which are called spikelets.

Diagram showing flowering spike diversity in the Grasses family: Spreeading panicle, flowering spike, Raceme & Compact panicle

If the flowering spike is unbranched, with each individual spikelet attached to the central stem by a stem (or rachis) it’s known as a raceme (as with Rye grass Lolium perenne and Tor grass Brachypodium pinnatum).

Racemes: Tor grass Brachypodium pinnatum and Italian Rye grass Lolium multiflorum

Panicles often refer to grasses whose spikelets are borne at the end of stalks on a branching flowering head.  They show an enormous amount of variety both in individual plants (depending on the age and developmental stage of the plant), within species, and (obviously) between species.

Variety of panicle shape: Yorkshire Fog Holcus lanatus showing one panicle still within the sheath, one fully spread at maturity.

Some other grass species with spreading panicles include Cocksfoot Dactylis glomerata, Common bent Agrostis capillaris, and Wavy hair grass Deschampsia flexuosa.

Spreading panicles in Cocksfoot Dactylis glomerata, Common bent Agrostis capillaris, and Wavy hair grass Deschampsia flexuosa

Panicles can also be very compact, and look like one tight structure.  This is particularly true of the Meadow foxtail Alopecurus pratensis.

Tight panicle shown by Meadow foxtail Alopecurus pratensis

Some other grasses with tight panicles include Crested Dog’s tail Cynosurus cristatus, Twitch grass Alopecurus myosuroides, and the Foxtails.

Tight panicles shown by Crested Dog’s tail Cynosurus cristatus, Twitch grass Alopecurus myosuroides

Grass Spikelets

Each individual spikelet, or flower, is made of distinct parts.  The stalk of each flower is called the rachis, and flowers are arranged alternately, or in a zig-zag fashion along it.

The base of each spikelet, be it one or several distinct flowers, is held in a pair of glumes.  These paired glumes have distinct upper and lower glumes, and these structures are important in determining grass species.

The glumes may have bristles or spikes attached to them.  These are called awns, and can be long or short, bent or straight, twisted (as with many Oat Avenaspecies), or absent.

Diagram of an individual grass flower or spikelet

Inside the glumes is the floret, which is the stamens and styles of each flower enclosed by two further scales or bracts, the lemma and the palea.  You’re down to hand lens work now, but characteristics to look out for are nerves along the middle (or lack of nerves), awns (or lack of awns), hairiness or not, and colour.

Normally, there are three stamens bearing anthers per spikelet; these often hang out beyond the flower; look closely to find purple ones (Timothy grass and Meadow Foxtail), orange ones (Orange foxtail), white, or cream anthers (many of the Bromes). False oat grass Arrhenatherum elatius has bright yellow stamens.

False oat grass Arrhenatherum elatius with yellow stamens and Meadow Foxtail Alopocerus pratensis with purple ones

Tillers

Some grasses put out lateral shoots, sometimes at quite a distance from the main plant.  These are known as tillers, and grow from horizontal rhizomes, or root-like stems which grow along the ground.  Grasses can rapidly colonise new habitats with this vegetative form of growth.

Tiller and rhizomes, shown on the Rough meadow grass Poa trivialis

Identifying grasses species: Features to look out for

Habit and habitat

What area is the grass growing in?  Is the ground wet or dry?  Calcareous or acidic?  Disturbed?  What season is it?

What shape and height is the plant?  Is it erect, tufted, or droopy?  Likewise, are the panicles tight or drooping, compact or loose, many branched or not?

Does it have rhizomes and tillers?

Leaves

How long and how wide are the leaves?  Are they hairy or smooth? Flat or inrolled and bristle-like? What colour are they?

Ligules

Fold the leaf blade back from the stem and find the ligule.  Look for its size, shape, edge, presence…

Spikelet

How are these arranged on the stem?  How big are they?  What colour? What texture?

Spikelet parts

Compare the size of the 2 glume scales, the number of nerves, awns or not, hairy or not.  Are the palea and lemma  awned or not?  How many nerves do they have?

Spikelets of False oat grass Arrhenatherum elatius and Common Oat grass Avena fatua

If you’re interested in learning more about British and European grasses, there are some really good reference books out there.  The “bible” of grasses is C.E. Hubbard’s Grasses; Colour Identification to the Grasses, Sedges, Rushes and Ferns of the British Isles by Francis Rose, Collins Guide to the Grasses, Sedges, Rushes and Ferns of Britain and Northern Europe by Fitter, Fitter and Farrer. You could also take a look at Collins Flower Guide by Streeter although it’s rather arrogant of me to suggest this as the grasses plates were all completed by me (with a great deal of help from David Streeter!)

I hope you’ll give the grasses a chance, and end up loving them as much as I do,  their beauty and diversity is mind-boggling.

The post Grass: An introduction appeared first on Lizzie Harper.

I recently taught a workshop at the wonderful Walled Garden in Treberfydd on flower anatomy.  I think it’s vital for botanical illustrations to be well-informed about their subject matter.  To this end I think botanical illustrators need to learn some of the basics of how flowering plants are put together.  One of the best ways to do this is to learn through drawing.  You can discover and learn as you explore a specimen.

We began with a brief overview of flower anatomy.  Obviously this varies enormously from family to family.   But if you can recognize basic parts such as the stamen, pistil, sepal, anther and style things become a little clearer as you draw.  For more on this, please check out my blog on basic botanical terms.

One of the diagrams on a handout on plant anatomy.  Dry, but important information

Drawing from life

We gathered some of the lovely plants at the Walled Garden.  The group observed, dissected, examined, and drew a variety of different shaped flowers.  They tried to find the anatomical features in each.  Sometimes these studies turn up new and exciting facts, I spotted stamens on the underside of iris petals (a fact I’d never clocked before) and we had a lot of fun sorting out the reproductive structures in a Salvia bloom.

Sketch examining the structure of a Cranesbill

Having a couple of good reference books on hand is always wise.  I had The Cambridge Glossary of Botanical Terms by Hickey and King, The Kew Plant Glossary by Henk Beentje, and Understanding the Flowering Plants by Anne bebbington, along with some trusty Stella Ross-Craig illustrations.

Studies of the anatomy of the Red campion, Silene dioica

I was lucky that my students were as excited and enthusiastic about discovering the minute details of the flowers they were examining as I was.  The time flew past.

Examining flowers with watercolour

I asked them to focus on one of the flowers they’d dissected and studied.  They used their watercolours to start a colour portrait.  So many flowers are in bloom at the Walled Garden that it was hard to choose an individual plant.  Finally they settled on a few.  Some painted Campanula (bell flowers), some chose Compositae daisies, and others turned their attention to the Geranium Cranesbills or Papaver Poppies.

Painting a bell flower, focussing on the lights and darks as well as the internal anatomy of the bloom

We talked about using watercolour, following the flow of the brush as you move the paint on the page and how important it is to make colours paler by mixing in water rather than adding white paint.

Laying down pale washes of Opera Rose pink watercolour on an illustration of a Poppy.

Lots of the flowers examined were bright pink, so we all tried out the ridiculously bright Opera Rose watercolour paint which is an absolute necessity for botanical illustration.

Watercolour studies of Studies of the anatomy of the Red campion, Silene dioica

A very delicious lunch was included in the price of the course.  It was made by Alison who owns the Walled Garden, using plants growing there.  Refreshed, we continued with the plant portraits.

Colour study of a Cranesbill cultivar

Once these portraits were completed, there was time for one more series of excersizes before the day finished.

Finishing up the petal details of the Bell flower

Painting white flowers

One of the ongoing problems for botanical illustrators is how to illustrate white flowers, which are very common.  The paper one paints on is white.  So the question is, what techniques can you use to show the distinction between paper and blossom?  I wanted to share some of these with my students.  (I’ve also done a blog on the topic).

First, we had a quick look at some of my botanical illustrations of white flowers.  I pointed out the four techniques I used to capture them.  First, put foliage behind them so they stand out.  Second, use pencil to outline the petals. Third, use very vey pale washes to give body to the white petals.  Finally, add an incredibly pale background wash to the paper behind the flower to provide contrast.

Various botanical illustrations by me of white flowers using a variety of techniques to illustrate the white petals.

I did a swift demo of how to keep washes very pale, and how to blend them imperceptably with the paper, then it was the student’s turn to give it a go.

Painting white flowers: In this instance the student has left pencil line, added very pale watercolour to the petals, and popped in a delicate green wash behind the flower.

You can use several of these techniques simultaneously, or each one in isolation.

Painting white flowers: Here the student has used a pale wash on the petals.  Once dry, they rubbed out the pencil lines.

Painting White flowers: Here another student has relied on pale pencil lines to show the edges of the petals

Painting white flowers: This student went for a heavier green background wash, along with foliage behind the white flower (Yellow flag iris study below)

As perhaps you can guess from the sketchbook page above, we also touched on mixing different yellows, looking for greens and oranges within these sunny hues.  I did a swift demo and some of the students had time to practice mixing up yellows for themselves.

By the end of the day the students had produced a lot of good work, and were thoroughly exhausted (anyone who says drawing and painting is relaxing has no idea!).  I know they went away inspired by the tiny details and function of flowers around us, and hope I managed to give them some tips on how to record these in pencil and in paint.

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Introduction to botany terms

This blog is an introduction to the basics of botany, so you can tell your corolla from your sepal, and your stem from your root.  Below is an annotated illustration of Lesser spearwort (Ranunculus flammula).

Many of these terms will be more than familiar; a leaf, roots, a stem, a bud, and a petal need no further explanation.

A petiole is a stem that bears a leaf.  The blade of a leaf is the flesh of it, and this is attached to a central midvein.

Botany: What is a flower?

In this illustration the term flower refers to the the part of a plant which has the potential to produce seeds; namely the reproductive organs (stamens and carpels), the coloured corolla (made of individual petals) which surround them, and the (frequently green) calyx which is made of individual sepals.  More on this below.

In botany, you often hear flowers referred to as the inflorescence of a plant.  Strictly, this not only includes the flower (as defined above) but also the part of a stem which bears these flowering parts.  Basically, anything above the last leaves on the stem is the inflorescence.

A sepal is the small (often) green leaf-like structure you often find under petals, or enclosing them whilst still a bud.  A calyx just refers to all the sepals surrounding one flower taken together.

Botany: Parts of a flower

So now we get to the nitty-gritty; the parts of a flower.  Bear in mind that there’s an enormous variety of form in flowers; and these terms have to be flexible enough to cover every plant species out there.  Just think of the difference in shape between a lousewort (Pedicularis sylvatica), a Knapweed flower (Centaurea scabiosa), and a morning glory (Ipomoea indica) and you’ll see what I mean.  For mroe of my flower illustrations, please visit the online gallery.

Here is a basic diagram of the parts of a flower (apologies for the pixelation):

Botany: The Corolla

Let’s start with the area surrounding the centre of the flower, which is often brightly coloured (and most of the reason why people think they’re so pretty).  This whole area is known as the corolla, and (as mentioned before) is made of petals.  Non-reproductive, the corolla is often used to dazzle and tempt potential pollinators to the flower.

Botany: Parts of the Male flower

Now for the male parts of our flower.  These are the stamens, and produce pollen.  Pollen is carried (by wind, water, or insect) to another flower of the same species to fertilize it.  Each stamen is made of a filament, or stalk, bearing an anther where the pollen is produced.  These can be all sorts of glorious colours, they’re very easy to see on florist’s lilies as they’re large and produce a vivid orange pollen.  The androecium refers not only to the male reproductive parts, but also to the ring or whorl which carries them. (A flower has, usually, four rings. From the outermost to the centre of the flower they are: the calyx, the petals, the androecium and, at the centre, the gynoecium).

Botany: Parts of the Female flower

The female reproductive part of a flower is made of reproductive units known as pistils or carpels. A carpel is a single (or a simple) pistil, and consists of the ovary, style, and stigma. One flower may have many carpels (for example, if you cut an apple in half there’s a star shape with a seed in each part.  Each of these chambers and seeds has arisen from one carpel, so an apple has 5 carpels.)  Another term used to describe the female parts of a flower is the gynoecium, this refers to all the pistils or carpels occuring in one flower.

Pistils are in the middle of the flower, and are typically made of a swollen base, the ovary, a style, and a stigma.  The ovary contains ovules, female reproductive cells or potential seeds; a stalk which comes out of the ovary (called a style), and a stigma.  The stigma is the tip of the style and is receptive to pollen grains whcih might land on it.  It is often sticky, as its job is to trap the pollen grains so they can burrow down the pollen tubes that they themselves create, into the ovary and fertilize the ovules with their male gamete, thus creating fertile and viable seeds.

The part of the plant to which the floral components is attached is the receptacle. The stem supporting the flower is known as the peduncle.

For another recap on these parts, please visit Teleflora’s site.

Conclusion

Hopefully this might help to clarify some of the basics.  Sometimes terminology seems terribly confusing, and this is because biological terms will sometimes overlap in meaning.  For more on flowers and the importance of their ovary position, keep your eyes out.  I’ll be blogging on it soon!

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Defining an Achene

The ACHENE is “a small dry indehiscent single-seeded fruit” (Flora of the Birtish Isles, Clapham Tutin and Moore). So far so good.  Yet under this umbrella definition is an enormous amount of variety.  The fruit of the buttercup and crowfoot is often referred to as a “typical achene”.  A typical achene is a fruit containing a single seed, where the fruit wall has hardened around the seed inside and thus covers it like a coat (without sticking to it).

Creeping buttercup

Explaining that definition!

INDEHISCENT means the fruit won’t open to disperse the seed at maturity.

Achenes only contain one seed.  Each achene is formed of this single seed produced by one carpel.  A CARPEL is one of the units that the GYNOECIUM is made from.  And a GYNOECIUM?  That’s the female parts of a flower.  It’s the ovary (which, when fertilized grows into the seed), the style, and the stigma.

Winged achenes

Sometimes, an achene can have wings. If so it’s called a SAMARA.  These wings are extensions of part of the tissue of the wall around the seed.  It grows outwards and flattens.  The purpose of these wings is to aid in wind dispersal, which explains why it’s mostly tree species who develop them.  Wings can grow on both sides of the seed; as in the case of the elm, bush willows, and hoptree.

Elm with winged achene (samara)

Samara can also have one wing or extension, leaving the seed at one end of the wing.  This is the case for maples (where these single winged samara are paired into the instantly recognisable shape), and for the ash.

Maple

The benefit for a tree of this design is that the seed “auto-rotates” as it falls, ensuring a clean and distant dispersal from the parent tree.  When something auto-rotates, it means that it goes on rotating as it falls through air in a steady fashion (as un-powered helicopter blades would do).  Try it next time you have a maple or ash key in your hand, it’s a nifty piece of aerodynamics.

Asteraceae and the achene

Asteraceae are plants made of two types of flower, ray and disk florets.  A common example is the daisy, and the dandelion.  Each yellow “dot” in the centre of a daisy is a single yellow disc floret.  Every white external “petal” is a ray floret.  Asteraceae species have different ray and disc florets according to species.  Across the entire botanical family (which used to be called Compositae), CYPSELA are their seeds.

Here we encounter a slight hiccough.  Some botanists claim that although cypsela are similar to achenes, they are, in fact, a different thing.  This is because they’re produced from a compound inferior ovary with one locule.  This means they’re produced by several ovaries which are joined together, each one of which is made of one chamber.  The whole lot is sited below the petals and rest of the female flower parts.

Most botanists agree that a cypsela is very similar to an achene.  They permit it to be used as the same umbrella term, hence it appears in this blog.

The dandelion seed, with its distinctive parachite, is a cypsela.  The fluffy part is made from part of the calyx, whose tissues have evolved into the intricate flying machine which attaches to each seed.

The sunflower seed is another example of a cypsela . The white or striped cover of the seed is the wall of the cypsela fruit.  Dissect a sunflower seed. See the hard outer coat and the seed inside; closely surrounded by -but not attached to- the fruit’s wall.

Within each rose hip, hidden amongst the hairs and the flesh, are a few achenes.

External achenes

For me, the most remarkable fact I found about achenes was they can be external.  The seeds that pepper the outside of a strawberry are all individual achenes.  Each one encases a single seed.  The delicious strawberry that we eat is, in fact, not a fruit at all (each of the strawberry pips IS a fruit).  It’s merely the sweet tissue which bears the achenes.

Other achene-bearing plants include: the tall anenome, cannabis, buck-wheat, crows-foot, lesser celendine, globe artichoke, spearwort, fleabane, zinnias, chrysanthemums, lettuce, marigold, echinacea…  Considering how many plants bear achenes, I reckon it’s worth knowing what one is.  Hopefully this blog has helped to explain just that.

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Sources of information on Fruit type

This got me thinking about how little I knew about  fruit types.  I thought if I blogged on the subject I’d learn a bit more.

I’m using the glossary from Flora of the British Isles by Clapham, Tutin, and Moore for my definitions (which I’ll quote, or paraphrase); it’s an eminently accessible and well-loved tome.  I used it throughout my work on the plates of the Collins Flower Guide by David Streeter.  It’s reccommended by both the Botanical Society of the British Isles (BSBI) and numerous botany departments of British colleges.

Defining terms used to describe fruit

Before we start on the fruit types, we need to define a couple of terms.  A CARPEL is an organ at the centre of a flower, which carries one or more OVULES (“an ovule is a structure containing the egg, and which develops into a seed after fertilization”), and whose margins fuse with other adjoining carpels to make a safe space where the ovules and ovary (and subsequently the seeds) are enclosed.  A GYNOECIUM is the female part of a flower (so the ovaries and, once fertilized, the seeds) along with the style and pistil.  A LOCULE is a segment, or chamber within the fruit.

Capsule

First up, the CAPSULE: “A dry dehiscent fruit composed of more than one carpel”.  If a fruit is dehiscent, it means it breaks open at maturity, in this case to spread the seeds.  The number of locules borne by a capsule varies from species to species, and mono/ bi/ tri-locular are just terms used to refer to these differences.  Examples of capsule-bearing plants are many lilies, the brazil nut, the horse chestnut, and the poppy family.

Berry

BERRY is a commonly used term, and (amazingly and luckily) mostly used in a botanically correct way. It’s a “fleshy fruit, usually several-seeded, without a stony layer surrounding the seeds.”  They’re produced from a single ovary. Lots of the fruit we eat are berries.  Blue-berries, gooseberries, grapes, tomato, elderberry come to mind.  Edible fruits we wouldn’t think of as berries are, (botanically), also berries.  These include pumpkin, watermelon, avocado, and coffee.

Legume

LEGUMES are dry fruit that develop from a lone or simple carpel.  They dehisce (break open) along two seams (one on each side) when ripe.  They are referred to as “pods”.  Think of the bean and the pea.  Any member of the Leguminosae (now called Fabaceae) have legumes.  Alfalfa, clover, letils, beans, lupins, peas, and vetch are examples.  Black locust (below) is one of the only legume-bearing trees.

Pome

POME are fruit “in which the seed is surrounded by a tough but not woody or stony layer, derived from the inner part of the fruit wall, and the whole fused with the deeply cup-shaped receptacle.” So pomes have seeds deep within thick layers (which, in the case of apples and pears, we eat).  You can see that it fuses with the receptacle because when you eat an apple, the stalk goes direct into the fruit. The “core” of an apple are the carpels, all fused together. Examples of pomes are apples, quince, pears, hornbeam, and hawthorn.

Cypsela

CYPSELA.  Ah, now here we get into some trouble.   Several fruit types explained here are actually different sorts of ACHENE.  An achene is a “small, dry indehiscent single-seeded fruit”.  In fact there’s such diversity in this definition that I’m going to do a whole blog on achenes.  For now though, a cypsela is an achene which develops from a compound inferior ovary.  They’re fruit of the Asteraceae family, so plants like dandelion and sunflowers.  If you think of a dandelion seed, the “wing” or parachute of it is actually an extension of the calyx (all the sepals), the seed and surround is the cypsela.

Achenes

ACHENE.  “a small, dry indehiscent single-seeded fruit”.  As I say, there’s tons of diversity wtihin this definition, mainly based on the position of the seed in the achene or the structures surrounding it.  Suffice to say that plants as diverse as the dandelion, elm, strawberry, rose, sycamore, and buttercup bear achenes.  As I mentioned earlier, next week’s blog’ll be all about achenes, so keep an eye out for it.

Drupe

Next up is the DRUPE, a “fleshy fruit with one or more seeds, each surrounded by a stony layer”.  Pretty straight-forward.  Drupes include damsons, plums, sloe, and ivy.

Caryopsis or grain

I’m afraid the CARYOPSIS is another form of achene.  It’s an achene where the ovary wall and seed-coat are united.  In effect, this means it’s a seed that’s only got one (fused) layer covering it.  This is the way that all the grasses and cereal crops bear their fruit, and the simplest way to think of it is as a lone grain of sweetcorn (maize); in fact “grain” is aonther word for a caryopsis.

Schizocarp

A SCHIZOCARP is an ovary formed of lots of fused carpels (SYNCARPOUS) that splits into separate segments when ripe; each segment has one seed.  It can also be defined as any fruit which splits into different portions when mature.  Examples of schizocarpous plants include carrots, mallow, and parsley.

Samara

I rather like the SAMARA, winged achenes; or “dry indehiscent fruit part of the wall of which forms a flattened wing”.  Trees often bear samara, and the wing is brilliant at using the wind to disperse.  Just watch a maple samara twist to the ground, or some ash keys helicoptering down.  Very clever.  Elms, the hop tree, ash, and maples all produce samaras.

Siliques

SILIQUES are specialised capsules which dehisce from below, with the ovary walls (the VALVE) lifting away to reveal the seeds supported by an internal scaffold (the REPLUM).  They’re formed of two fused carpels, and their length has to be more than 3x their width.  Examples include radish, bittercress, and oil-seed rape.

Nuts

Wa all know what a NUT is, and eat lots of different types.  They tends to be single seeds encased in a hard outer ovary wall which doesn’t dehisce or easily part from the wall (or “shell”) at maturity.  The ovary wall tends to be woody, and true nuts develop from compound ovaries.  Species bearing nuts include hazel, chestnut, beech, and oak.

Follicle

Finally, the FOLLICLE is a “dry dehiscent fruit formed of one carpel, dehiscing along one side”.  It has two or more seeds which get dispersed when the follicle splits along one seam at maturity.  Examples include the peopny, milkweed, hellbore, larkspur, and aquilegia.

And that’s it!  Most of the different terms for a fruit defined.  I feel it’s one of these areas where if I use the terminology more then I’ll get used to it, and no longer feel over-whelmed by so many terms and definitions.  And certainly, for me, matching a plant to its’ fruit type has been highly instuctive.  I just hope I’ve not bored you to tears as I did it!

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Monocots vs Dicots

In order to illustrate grasses, you need to know a bit about their anatomy.  They are unlike many of our plants as they are monocots not dicots.  This basically means that their seeds are formed of one cotyledon not two, but there are other more obvious differences.

Features of Monocots

Monocot leaves grow mainly from the base of the plant, rather than up a stem.  This means when they are grazed the plant does not die, and has much to do with their ubiquitous prescence and enormous success.  Leaf veins run parallel rather than in a net across the leaf.  The roots of monocots grow in fibrous bundles, rather than branching from one main tap root. This enables them to efficiently gather nutrients as most of these are absorbed by root hairs, which are abundant in these bundles.  These roots are adventitious and spread swiftly; many moncots reproduce vegetatively by producing stolons (runners), horizontal stems which produce leaves.  Below ground, monocots may have rhizomes which can produce whole new plants at their nodes.  Good tactics for maximizing spread.

The vascular tissue of monocotstends to be in bundles rather than a ring (as in dicots) and never forms wood.  Flowers tend to have 3 parts (or multiples of 3), whereas dicots produce these in 5s, or multiples of 5.  Like the dicot plants dandelion and hazel, grasses are wind pollinated.

Grasses and wind pollination

Wind pollinated plants, for The Complete Naturalist by Nick Baker.

(For more information on monocots vs dicots please follow the Berkeley College link.

Anatomy of Grasses: The Plant

A grass plant consists of long leaves (or blades) at the base of which there may be a ligule (see below).  The blades grow from a hollow and rounded stem (or culm).  These stems are enclosed in the grass sheath, and jointed at the nodes.  The flowering part of a grass plant is called the panicle or flower-head or (if it’s unbranched), the raceme.

The Ligule

The ligule is a little membranous flap which can be seen at the base of the blade (occasionally represented by a fringe of hairs), where it joins the sheath (and often the stem).  You may need a hand lens to see it, and in some species it is absent.  However, ligule length and shape, and whether it’s smooth or torn, are crucial diagnostic tools in identifying grasses.  Below are some different shapes of ligule.

The Inflorescence

The flower-heads of grasses are formed of spikelets (individual grass flowers) which are arranged in different ways: attached to the stem with a stalk in a raceme(like false brome), or in stalked flowering spikes (like rye and wheat).  Panicles occur when spikelets are borne on stalks in branching flower heads.  These can be spreading (like annual meadow grass, Yorkshire fog, Cocksfoot); or compact (timothy grass, foxtails, crested dog’s hair grass).

The Spikelet

The spikelet is an individual unit of a grasses flowering head, and consists of the flower enclosed by a pair of scales (glumes) which may or may not have spines (awns).  Inside the glumes is the floret, which is the stamens and styles of each flower enclosed by two further scales, the lemma and the palea.  These scales may have awns and may/ may not have nerves (like visible lines).  Below are un-annotated and annotated diagrams of a grass spikelet.

Identifying grasses species: Features to look out for

• Plant Check for habitat, the way it grows (habit), size of leaves, height, way the flower-heads are arranged and hang, season.

• Leaves Are the leaves are smooth/ hairy, inrolled or flat, their length, their width, anything interesting abour their tips (eg spiky), colour

• Ligule Look for one by gently folding the blade back from the stem.  Look for it’s size, shape, edge (torn or smooth).  If not there that’s another diagnostic!

• Spikelet How are these arranged on the stem?  Size of individual spikelets, colour, texture, size of component parts…

• Glume Comparative size of the 2 scales, number of nerves, awns or not, size, hairy or not

• Palea and lemma Are these awned or not?  How many nerves do they have?

A few amazing species of grass can produce tiny new plants from their flower heads.  These are called viviparous grass and look pretty peculiar.

HarperCollins Flower Guide Grasses Plates

My love of grasses was ignited when I illustrated the grasses plates for the Collins Flower Guide by David Streeter. David would send me samples in the post, of ever more extraordinary and beautiful grasses. I worked closely with him, and consulted my grasses “bibles” frequently.  These are C.E. Hubbard’s Grasses, Colour Identification to the Grasses, Sedges, Rushes and Ferns of British Isles and North Western Europe by Francis Rose, and Collins Guide to the Grasses, Sedges, Rushes and Ferns of Britain and Northern Europe by Fitter, Fitter and Farrer.

Below are three of the twenty or so botanical plates of grasses I did for the flower guide; they’re some of the work I am most proud of having done to date.

Uses of Grasses

Grasses are not the only monocot plants, but they are incredibly important to humanity and have adapted to live in habitats as diverse as sand dunes (marram), mountainous scree (alpine hair grass), and can even grow underwater (the common reed, pictured below).

They are vital food crops; all cereals are grasses.  Below are six of the most common.

My love of grasses

Despite their abundance, beauty, importance and diversity; grasses are often overlooked.  They deserve more recognition, and reward interest and the time it takes to get to grips with their terminology and anatomy.  They are, without doubt, one of my very favourite subjects to paint; from the pinkish flush of each spikelet of a Yorkshire fog plant to the brownish yellow areas of wear and tear on the leaf of a rye grass.  You can keep your blousy roses and violet irises, I’m obsessed with the grasses and I’m happy to keep it that way.

Rye grasses x 2 Lolium perenne and Lolium multiflorum

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