Stem:  The modified stem is very short and grows partly underground.

Flower: The small flowers lack petals or sepals. There are 3 types of flowers on each plant: bisexual flowers and male flowers are small, greenish, and occur in short spikes (0.5-4 cm) on long stalks (3-20 cm); female flowers occur singly near the base of the plant and are enclosed in the leaf sheaths. 

Fruit: The strongly-ribbed woody nutlets are 2-10 mm long and have a beaked tip.

Root: Fibrous roots emerge from a modified stem that grows partly or completely below the ground.

Propagation: The plant spreads by seeds which are probably dispersed by water. 

Importance of plant: Unknown, but the fibrous roots may help stablize sediments.

Distribution: North and South America from Canada to Chile, and also in Australia.  

Habitat: Shallow water in alkaline, saline, or brackish areas from coastal tideflats to interior valleys. Often found growing in sediments at the edge of receding water.

May be confused with: Quillworts (Isoetes), which have distinctly swollen leaf-bases containing spores and are strictly freshwater plants. Other low-growing, shallow water plants such as awlwort (Subularia aquatica), water lobelia (Lobelia dortmanna), lilaeopsis (Lilaeopsis occidentalis), and mudworts (Limosella). Look for differences in leaf and flower structure to distinguish them.

Photographs:  http://www.npwrc.usgs.gov/resource/othrdata/westflor/species/4/lilascil.htm

Line Drawings:
http://www.npwrc.usgs.gov/resource/othrdata/westflor/species/4/lilascil.htm