Callitriche trochlearis
Callitriche heterophylla
effluent water-starwort, water starwort, wheel fruit water-starwort
different-leaf water-starwort, diverse-leaf water-starwort, greater water-starwort, large water-starwort, prairie sandgrass, two-head water-starwort, variedleaf waterstarwort, water starwort
and leaf scales present.
and leaf scales present.
connate at base, ± parallel-sided, 5.2–9.1 × 0.1–0.9 mm, 1+-veined.
connate at base, ± linear, tapering from near base or spatulate, 3.7–24.7 × 0.3–3.5 mm, 1+-veined.
bracts persistent.
bracts caducous.
0–0.5 mm in fruit.
0 mm in fruit.
usually 1 staminate and 1 pistillate in each axil;
styles spreading;
pollen yellow.
usually solitary;
styles erect or spreading;
pollen yellow.
1–1.2 × 1.1–1.3 mm, ± as long as wide;
mericarps black, not swollen, evenly winged throughout, wings straight, 0.05–0.1 mm wide.
± round, (0.4–)0.5–0.9(–1.2) × 0.5–1(–1.2) mm, as long as wide;
mericarps black, not swollen, not winged or winged only at apex, wings straight, 0.05–0.1 mm wide.
= 40.
Callitriche trochlearis
Callitriche heterophylla
Callitriche trochlearis occurs in northwestern and central-western California plus western Oregon.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Two varieties have been recognized in Callitriche heterophylla, with var. bolanderi distinguished on the basis of its schizocarps being larger (for example, N. C. Fassett 1951b); however, the size of the schizocarps overlaps widely, and measurements of schizocarps from throughout North America show that there is no clear geographical or ecological separation between plants with smaller fruit and those with larger fruit. Therefore, there is no justification for maintaining the distinction.
Populations of small plants with linear leaves from parts of Canada and Alaska have been separated as Callitriche anceps. However, these appear to represent the lower extremes of variation in C. heterophylla, and morphological characters do not justify maintaining the distinction.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
