Trifolium bifidum
Proc. Calif. Acad. Sci. 3: 102. 1864.
Herbs annual, 5–55 cm, sparsely pubescent or glabrous. Stems erect, branched. Leaves palmate; stipules ovate to lanceolate, 0.8–1.5 cm, margins entire or slightly serrate, apex acicular; petiole 1–7 cm; petiolules to 0.5 mm; leaflets 3, blades narrowly obcordate, obovate, oblanceolate, or linear, 1–2.5 × 0.3–0.7 cm, base cuneate, veins moderately thickened, margins serrate distally or entire, apex rounded, truncate, shallowly to deeply retuse, or deeply 2-fid, surfaces glabrous or hairy abaxially along midvein. Peduncles 3–8 cm. Inflorescences axillary or terminal, 5–30-flowered, globose to subglobose, 0.8–1.5 × 0.8–1.5 cm, rachis prolonged beyond flowers; involucres a very narrow rim, to 0.5 mm. Pedicels reflexed in fruit, 1–3 mm; bracteoles broadly triangular, membranous, to 0.5 mm. Flowers 6–8 mm; calyx campanulate, 3–3.6 mm, slightly hairy or glabrous, veins 10, tube 1–1.5 mm, lobes unequal, subulate, margins green or purple, orifice open; corolla pink or purple, 5–7 mm, banner elliptic to oblong, 5–7 × 3–4 mm, apex rounded, apiculate. Legumes stipitate, obovoid, 3–4 mm. Seeds 1 or 2, brown, mottled, oblong, 2–3 mm, smooth. 2n = 16.
Phenology: Flowering Apr–Jun.
Habitat: Open woodlands, fields, roadsides, slopes, stream margins, meadows.
Elevation: 0–1200 m.
Distribution
B.C., Calif., Oreg., Wash., Mexico (Baja California).
Discussion
Trifolium bifidum ranges from Baja California, Mexico, northward through California to scattered sites in Oregon, Washington, and British Columbia.
Recent re-evaluation of Trifolium bifidum and related species showed complete overlap in characters for the two varieties that have been recognized previously, with no clear distinctions between them (L. Rogers, pers. comm.).
Selected References
None.