hollow stems

Giant Hogweed Heracelum mantegazianum sketchbook studies showing detail of leaves, stem, and seeds.

Persian Hogweed Heracelum persicum and Giant Hogweed Heracelum mantegazzianum comparison with info on flower shape, umbel shape, and leaf differences

Giant Hogweed Heracleum mantegazzianum habit drawing

Watercress Nasturtium officinale with flower and seeds and edible leaves

Tubular water dropwort Oenanthe fistulosa in amongst grasses with flowering head and seed head, and showing the stem swelling as well as leaves

Reed Phragmites australis

Giant hogweed Heracleum sphondylium with stem cross section and lots of leaves