USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Aquatic and Wetland Vascular Plants of the Northern Great Plains

34. Apiaceae, the Parsley Family

3. Sium L. -- Water parsnip

1. Sium suave Walt.


Stout, fibrous-rooted perennial 4-20 dm tall, from a short erect crown; stems solitary, strongly ribbed upward, thickened and hollow with cross-partitions at the base, partitioned at the nodes above. Leaves once-pinnate, the blades oblong to ovate in outline, 5-25(35) cm long, 6-20(30) cm wide; leaflets usually 7-17 per leaf, linear to lanceolate, 3-15 cm long, 3-15 mm wide, sharply serrate; petioles long below, shorter upward, hollow, septate-nodulose; submersed leaves often present early in the season, finely bipinnately dissected. Umbels terminal and lateral, few to many, 4-12 cm wide in fruit, on peduncles 3-10 cm long; rays 1.5-4 cm long; bracts 6-10, narrowly lanceolate, entire or incised, reflexed; umbellets 7-12 mm wide, the pedicels 3-5 mm long; bractlets 4-8, smaller than the bracts, entire. Flowers white or greenish-white, 1.5-2 mm across; sepals minute or none. Fruits oval to orbicular, 2-3 mm long, slightly constricted on the commissure, the ribs prominent and corky, subequal. Jul--Sep. Marshes, swamps, springs, ditches and margins of streams, ponds and lakes, often emergent; common; (Newf. to B.C., s to FL, TX and CA).
GIF- Distribution Map

Map key


Previous Section -- Cicuta maculata L. -- Common water hemlock
Return to Family -- Apiaceae - The Parsley Family

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/plants/vascplnt/species/sium.htm
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:47:16 EST
Sioux Falls, SD [sdww55]