Contr. U.S. Natl Herb. 4: 115 (1893) APNI
Threat status:Victoria: data deficient (k)
Aquatic or semi-aquatic herb 30–100 cm high; stems branched, hollow, striate to furrowed. Emergent leaves once-pinnate, submerged leaves 3–4-pinnate, lamina 12–40 cm long, 1.5–12 cm wide; leaflets 15–21, oblong-lanceolate or c. ovate, 8–56 mm long, 4–35 mm wide, toothed, sessile. Umbels 3–6 cm diam.; peduncles 3–8 cm long; bracts lanceolate, uneven, 10–20 mm long; rays 6–20, unequal, to 20 mm long; umbellules 6–12 mm diam., 9–22-flowered, bracteoles linear or lanceolate, 2–3.5 mm long; pedicels to 5 mm long. Petals c. 1 mm long, white. Fruit 1.5–2 mm long.
HSF, *EGL, *EGU, *GipP, *VVP, *WaP, *WPro. Also naturalised WA, SA, Qld, NSW, Tas. Native from Europe to central Asia, and North America. Occurring in lowland, often near-coastal, swamps and streams in southern Victoria. Flowering Dec.-Mar.
This species is now generally accepted as a natualised alien in Australia but was once regarded as an indigenous variety (univittatum) of the European Sium latifolium.
This species is often confused with Helosciadium nodiflorum which has 0–2 bracts at the base of the umbels.
|Bioregion||Occurrence status||Establishment means|
|Victorian Volcanic Plain||present||introduced|
|East Gippsland Lowlands||present||introduced|
|East Gippsland Uplands||present||introduced|
|New South Wales|
|Australian Capital Territory|