Trifolium wormskioldii
Trifolium buckwestiorum
coast clover, cow clover, cows clover, salt marsh clover, springbank clover, wormskjold's clover
Santa Cruz clover
erect, ascending, or decumbent, branched.
decumbent to ascending or erect, slightly branched.
palmate;
stipules ovate to lanceolate, 1.5–2 cm, margins entire (proximal stipules) or lacerate (distal stipules), apex acute to acuminate;
petiole 1–11 cm;
petiolules 0.5 mm;
leaflets 3, blades obovate to elliptic, 0.4–4.2 × 0.2–1.3 cm, base cuneate or rounded, veins fine or thickened distally, margins spinulose-serrate, apex usually acute to rounded, sometimes retuse or mucronate, surfaces glabrous.
palmate;
stipules whitish with prominent green veins, ovate, 0.3–0.5 cm, margins lacerate, apex acute to acuminate;
petiole 1–2.4 cm;
petiolules to 0.5 mm;
leaflets 3, blades obovate to elliptic, 0.6–1.5 × 0.3–0.8 cm, base cuneate, veins ± thickened distally, margins denticulate, sometimes entire proximally, apex rounded, acute, or retuse, surfaces glabrous.
axillary or terminal, 20–50-flowered, subglobose or globose, 1.8–2.5 × 2–2.5 cm;
involucres broadly bowl-shaped, 12–20 mm, incised 1/3–1/2 their length, lobes 10+, sharply and acutely serrate, veins prominent.
terminal or axillary, 15–20-flowered (early inflorescences hidden in stipules, subsessile, 2–5-flowered, flowers cleistogamous), subglobose, 0.5–0.8 × 0.6–0.8 cm;
involucres flattened or shallowly bowl-shaped, 6–8 mm, when folded, nearly hiding calyces, glabrous or sparsely hairy, lobes 4 or 5, ± parallel-sided, 3 or 4-toothed.
1.5–11 cm.
1–3.5 cm.
straight, 1.5–2 mm;
bracteoles linear or ovate, 1–2 mm.
straight, to 0.5 mm;
bracteoles absent.
12–14 mm, odor somewhat unpleasant;
calyx whitish, tubular, 5–6 mm, glabrous, veins 10, tube 2–3 mm, lobes green to purple, subequal, abaxial rarely longer than tube, orifice open;
corolla usually magenta to purple, rarely white or bicolored, 10–12 mm, banner ovate-oblong, 12–14 × 2–3 mm, apex truncate or rounded, slightly retuse.
7–8 mm;
calyx tubular, 4–5 mm, glabrous, veins 10, tube 2–2.5 mm, lobes subequal, triangular, margins conspicuously 2 or 3-toothed, apex aristate, orifice open;
corolla pale pink or white, 6–7 mm, banner oblong, 5–7 × 1 mm, apex emarginate or erose.
oblong, 2–4 mm.
ovoid, 2.5 mm.
3 or 4, brown, sometimes mottled, subglobose or mitten-shaped, 1.5 mm, smooth.
1, dark brown, slightly mottled, ovoid, 2 mm, smooth.
= 16, 32.
Trifolium wormskioldii
Trifolium buckwestiorum
Trifolium wormskioldii is largely tetraploid and is widespread in western North America. Distinguishing T. wormskioldii from closely allied species (especially T. mucronatum) is sometimes difficult, which led R. C. Barneby (1989) to synonymize T. mucronatum and T. pinetorum under the former name. Trifolium wormskioldii produces long, white rhizomes; T. mucronatum produces only short rhizomes at most, often only small, fibrous roots or taproots (J. M. Gillett 1980). The distinction of T. pinetorum from T. wormskioldii was supported by N. W. Ellison et al. (2006); those authors did not include material of T. mucronatum in their DNA analyses.
Trifolium wormskioldii rhizomes may have been a food resource for Native American groups in the Pacific Northwest (N. J. Turner and H. V. Kuhnlein 1982).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Trifolium buckwestiorum, which ranges from Mendocino to Monterey counties, is unique among clovers in North America because of its aboveground cleistogamous, axillary flowers. The only other clover in North America that produces cleistogamous flowers is T. amphianthum, which produces its cleistogamous flowers at ground level and then pushes them into the substrate.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
