Trifolium bifidum |
Trifolium stoloniferum |
|
---|---|---|
notch-leaf clover, Pinole clover, piñole clover |
running buffalo clover |
|
Habit | Herbs annual, 5–55 cm, sparsely pubescent or glabrous. | Herbs perennial, 10–20 cm, glabrous or sparsely pubescent. |
Stems | erect, branched. |
creeping, branched, rooting at nodes. |
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. |
palmate, opposite or subopposite on erect stems; stipules lanceolate (on prostrate stems) or ovate (on erect stems), 1–2 cm, margins entire or shallowly serrate, apex acuminate; petioles 6–15 cm on prostrate stems, 0.5–4 cm on erect stems; petiolules 1 mm; leaflets 3, blades broadly ovate or obcordate, 1–2 × 0.5–2.5 cm, base broadly cuneate to rounded, veins fine, margins serrate, apex emarginate or rounded, surfaces glabrous. |
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. |
terminal, single or paired at tip of upright stem, 15–30-flowered, globose, 2–3.5 × 2–3.5 cm; involucres absent. |
Peduncles | 3–8 cm. |
2–7 cm. |
Pedicels | reflexed in fruit, 1–3 mm; bracteoles broadly triangular, membranous, to 0.5 mm. |
elongated and strongly reflexed in fruit, 2–5 mm; bracteoles lanceolate, 2 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. |
9–15 mm; calyx campanulate, 4–7 mm, glabrous or sparsely pubescent, veins 10, tube 1.3–3.3 mm, lobes subequal, subulate, orifice open; corolla white, veins often pinkish, 8–14 mm, banner ovate or oblong, 8–14 × 4–5 mm, apex rounded or emarginate. |
Legumes | stipitate, obovoid, 3–4 mm. |
oblong, 2.5–3 mm. |
Seeds | 1 or 2, brown, mottled, oblong, 2–3 mm, smooth. |
1 or 2, tan to brown, reniform, 1.3–2 mm, smooth. |
2n | = 16. |
= 16. |
Trifolium bifidum |
Trifolium stoloniferum |
|
Phenology | Flowering Apr–Jun. | Flowering Apr–Jun. |
Habitat | Open woodlands, fields, roadsides, slopes, stream margins, meadows. | Grassy openings in upland woods. |
Elevation | 0–1200 m. (0–3900 ft.) | 150–900 m. (500–3000 ft.) |
Distribution |
CA; OR; WA; BC; Mexico (Baja California)
|
IN; KY; MO; OH; PA; WV |
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.). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Trifolium stoloniferum was thought to be extinct but was rediscovered in the early 1980s (R. L. Bartgis 1985). It is now known from extant populations scattered throughout much of its original range, in five of the original eight states in which it was found historically (D. J. Crawford et al. 1998); it was discovered in Greene County, Pennsylvania, in 2017, but appears to be extirpated in Arkansas, Illinois, and Kansas. R. J. Hickey et al. (1991) examined genetic diversity of T. stoloniferum populations using allozymes and found low diversity, with some populations appearing genetically uniform. Molecular studies using RAPDs (Crawford et al.) indicated somewhat higher genetic diversity, even in relatively small populations. Trifolium stoloniferum is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | Fabaceae > subfam. Faboideae > Trifolium | Fabaceae > subfam. Faboideae > Trifolium |
Sibling taxa | ||
Synonyms | T. bifidum var. decipiens, T. greenei, T. hallii | |
Name authority | A. Gray: Proc. Calif. Acad. Sci. 3: 102. (1864) | Eaton: Man. Bot. ed. 2, 468. (1818) |
Web links |
|