Plants of South Eastern New South Wales

Nasturtium officinale

Flowering and seeding stems. Photographer Don Wood, Blundells Flat, ACT

Flowering plant. Photographer Keir Morse, California, USA

Open 'pods'. Photographer Zoya Akulova, California, USA

Line drawing in Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. Vol. 2: 162

Common name

Watercress

Family

Brassicaceae

Where found

In mud or shallow water. Widespread.

Notes

Introduced perennial herb to 2.5 m high or sprawling, stoloniferous. Stems angular, hairless, hollow. Leaves alternating up the stems, 2-12 cm long, hairless, deeply dissected or compound, with 3-11 lobes or leaflets, the terminal lobe larger, margins scalloped to entire. Leaves becoming smaller up the stems. Flowers with 4 white petals each 2.5–6 mm long. Flowers in clusters of 10-25 flowers. Flowers spring–autumn. 'Pods' straight or curved, 1–2 cm long, 2–2.5 mm wide, pointing up or spreading, stalks spreading to pointing down, 8–15 mm long. Seeds in 2 rows on either side of a central division.

Reliable differentiation of this species from Nasturtium microphyllum requires examination of the arrangement of the seeds in the 'pods', and often microscopic examination of a seed.

PlantNET description:  https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Nasturtium~officinale  (accessed 20 April 2021)