Southwestern starwort is a tiny short-lived perennial aquatic or semi-aquatic species found primarily in North America in the western half of of the United States and one Canadian province (British Columbia) (USDA 2011). In British Columbia, it is found in wet ditches, mudflats and shallow ponds and shorelines in the lowland, steppe and montane zones, where it is rare in extreme SW and SC BC (Douglas et al. 1999). Lomer (2011) describes this species in the Fraser Valley: "A small prostrate annual of wet muddy sites, often half buried. It grows in the wettest depression pools on tidal mudflats and flood pools along the Fraser, Pitt and Harrison Rivers. 14 sites are known in Greater Vancouver, all along the riverflats, except for one site on the shore of Latimer Lake in Surrey, where it is very scarce and was not found in recent years. It will rarely show up from time to time in Fraser River sand dredgings used as preload in preparation for building construction (UBC: Lomer 97-604)." (Reprinted from Botanical Electronic News # 435, with permission)

General:
Annual or short-lived perennial, aquatic or semi-aquatic herb; stems prostrate to erect, 3-10 cm long.

Leaves:
Opposite, simple, oblong-lanceolate, short-stalked, tips blunt to notched, 0.8-1.2 cm long.

Flowers:
Inflorescence of 1 or 2 axillary flowers per node; petals reddish, 3, widely elliptic; sepals usually 2; stamens 3, opposite the sepals.

Fruits:
Capsules, 3-chambered; seeds narrowly oblong, straight or slightly curved, pitted in longitudinal rows.

Source:  The Illustrated Flora of British Columbia

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source:  The Illustrated Flora of British Columbia

Synonyms and Alternate Names:
Elatine triandra Schkuhr