E-Flora BC: Electronic Atlas of the Flora of British Columbia

Callitriche heterophylla Pursh
large water-starwort (diverse-leaved water-starwort; prairie sandgrass; twoheaded water-starwort)
Plantaginaceae (Mare's-tail family)
(Previously in Callitrichaceae)

Introduction to Vascular Plants
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Distribution of Callitriche heterophylla
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Species Information

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Aquatic or semi-aquatic perennial rooting in mud; stems leafy, 2-40 cm long, with or without small membranous ridges between the leaf-bases.
All opposite; submerged leaves linear, single-veined, notched at the tip, 5-25 mm long; floating and emergent leaves broadly egg-shaped or oblanceolate, 3-veined, up to 1 cm wide.
Inflorescence of tiny, inconspicuous flowers borne with a pair of tiny bracts, stalkless or shortly-stalked; styles 1-5 mm long, ascending.
Achene-like, 4, each 1-seeded, wingless or scarcely wing-margined, rounded, egg-shaped or heart-shaped, irregularly pitted.
Two subspecies occur in our region.

1. Fruits egg-shaped or slightly heart-shaped in outline, broadest above the middle; submersed leaves usually wider than the stem; plants long-stemmed........................ ssp. bolanderi (Hegelm.) Calder & Tayl.

1. Fruits usually more nearly round or egg-shaped in outline; submersed leaves much narrower than the flattened stem; plants short-stemmed....................... ssp. heterophylla

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Fruit/Seed characteristics:
Colour: Green
Present from Summer to Fall
Source:  The USDA

Habitat / Range

Shallow ponds, slow-moving streams and shorelines in the lowland and montane zones; ssp. bolanderi- frequent on S Vancouver Island, rare in SE BC, ssp. heterophylla - rare in coastal BC; N to AK, YT, NT, E to NF and S to GA, TX, OK and CA; South America (ssp. bolanderi).

Source: The Illustrated Flora of British Columbia


Ecological Framework for Callitriche heterophylla

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 0 293 1158
Slope Gradient (%) 0 0 1
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
6 7 8
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: CDF(1), CWH(3), SBPS(1)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Taxonomic and Nomenclatural Links

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General References