Trifolium bifidum |
Trifolium nigrescens |
|
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notch-leaf clover, Pinole clover, piñole clover |
small white clover |
|
Habit | Herbs annual, 5–55 cm, sparsely pubescent or glabrous. | Herbs annual, 10–60 cm, glabrous or glabrescent. |
Stems | erect, branched. |
usually erect or ascending, rarely prostrate, 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. |
palmate; stipules triangular-lanceolate, 0.4–0.8 cm, margins entire, apex dark purple or reddish, sharply recurved, subulate; petiole 0.5–10 cm; petiolules 0.5 mm; leaflets 3, blades obovate or obtriangular, 0.5–2.5 × 0.3–2.5 cm, base cuneate, veins fine, margins denticulate, apex rounded to emarginate, 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. |
axillary or terminal, 15–50-flowered, globose, 1–1.8 × 1–1.8 cm; involucres a narrow rim, to 0.2 mm. |
Peduncles | 3–8 cm. |
1.5–4 cm. |
Pedicels | reflexed in fruit, 1–3 mm; bracteoles broadly triangular, membranous, to 0.5 mm. |
reflexed in fruit, 3–6 mm; bracteoles narrowly oblanceolate, 3–6.5 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. |
6.5–9 mm; calyx oblong, 3–5 mm, glabrous or pubescent, veins 5–10, tube 1–2.5 mm, lobes ± equal or unequal, triangular-lanceolate, recurved in fruit, margins green or purple, apex acute to acuminate, orifice open; corolla pink or white, 6–9 mm, banner obovate-oblong, 6–9 × 1–2 mm, apex acute to emarginate. |
Legumes | stipitate, obovoid, 3–4 mm. |
linear-oblong, 3–4.5 mm. |
Seeds | 1 or 2, brown, mottled, oblong, 2–3 mm, smooth. |
1–5, yellow or pale or dark brown, oblong, 1 mm, smooth. |
2n | = 16. |
= 16. |
Trifolium bifidum |
Trifolium nigrescens |
|
Phenology | Flowering Apr–Jun. | Flowering Mar–Oct. |
Habitat | Open woodlands, fields, roadsides, slopes, stream margins, meadows. | Roadsides, lawns, fields, waste places. |
Elevation | 0–1200 m. (0–3900 ft.) | 0–200 m. (0–700 ft.) |
Distribution |
CA; OR; WA; BC; Mexico (Baja California)
|
AL; FL; GA; LA; MS; TN; TX; s Europe; w Asia; n Africa [Introduced in North America] |
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 nigrescens was shown, using molecular markers, to consist of three subspecies and to hybridize readily with T. repens (W. M. Williams et al. 2001). It was first introduced as a potential crop species in the early 1950s and is cultivated widely in the southeastern United States as a forage crop and as a nitrogen source in roadside grass plantings (C. S. Hoveland 1960). (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) | Viviani: Fl. Ital. Fragm., 12, plate 13. (1808) |
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