Syn.: Cicuta dahurica Fisch., Sium cicutifolium Schrenk, Sium floridanum Small, Sium formosanum Hayata, Sium nipponicum Maxim.
Family: Apiaceae Lindl.
Distribution: Amphipacific species found in major part of North America (rarer in US south, absent in Oklahoma, and in northeast Canada) and also in eastern Asia (Russian Far East, Korea, Japan, Taiwan and Chinese provinces Hebei, Heilongjiang, Jilin, Liaoning, Nei, Mongol, Ningxia and Shandong).
Ecology: Grows in wet meadows, marshes, close to water. Blooms in July and August.
Description: Perennial herb, 60–120 cm tall, shallow fibrous, fleshy roots. Stem erect, lower leaves petiolate, ovoid, 6.25 × 7–10 cm, compound, 3–9 leaflets, lanceolate to linear, margins dentate, upper leaves smaller, 3-lobed, sessile. Inflorescence terminal compound umbel, 5–15 cm across, 8–22 secondary umbels, each 20–35 flowers; flowers 3 mm across, 5 white petals, incurved tips, light green calyx, slightly dentate; twin ovary, two divergent styles. Peduncle and pedicels angular or finely grooved. Fruit is a schizocarp, divided into two seed, about 3 mm long, compressed and strongly ribbed.
Use: This plant is used medicinally and it is used in Chinese traditional medicine. The roots are edible and were collected by native tribes.
Caution: Sium suave is very similar to Water Hemlocks (Cicuta) which are sympatric but extremely poisonous.
Note: Genus Sium contains about 10 species found in Europe, Asia, North America and Africa.
These images were taken in Canada, Alberta, Calgary, South Glenmore Park (August 2013).
