Nasturtium officinale W.T. AitonWatercress | |
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Introduced CC = * CW = -5 MOC = 48 |
© DETenaglia |
Family - Brassicaceae Stems - To +60cm long(tall), erect to ascending or creeping, from taproot and fibrous roots (often rooting at nodes), herbaceous, glabrous, fistulose.
Leaves - Alternate, odd-pinnate, petiolate, to +15cm long, glabrous. Petiole partially clasping the stem. Leaflets 3-11, opposite to subopposite, sessile, oblique at base, ovate-lanceolate, often emarginate at apex, to +2cm long, +1cm broad, entire to irregularly shallow crenate.
Inflorescence - Compact terminal racemes, quickly elongating in fruit to +20cm long. Pedicels glabrous, 2-7mm long in flower, elongating in fruit. Flowers - Petals 4, free, white, clawed, glabrous. Claw to 2mm long. Limb rounded at apex, 3mm long, 2mm broad. Stamens 6, with 4 long and 2 short. Shorter staens opposite and outside of longer stamens. Filaments purplish, glabrous, 3.5mm long. Anthers yellow. Ovary terete, purplish-green, 2.5mm long, glabrous. Style very short or wanting, persistent in fruit as beak. Stigma 2-lobed, capitate. Sepals 4, free, glabrous or with a few minute strigose hairs at apex, 3mm long, 1.2mm broad, often with revolute margins. Siliques to +1.5cm long, terete, glabrous, many-seeded.
Flowering - April - October. Habitat - In water and on wet ground. Origin - Native to Eurasia. Other info. - Nasturtium is a fairly common plant throughout the southern half of Missouri but is also found in a few counties north of the Missouri River.
Photographs taken at the Parkville Nature Sanctuary, Parkville, MO., 5-12-00, and in Iron County, MO., 5-18-03. |