Trifolium tomentosum |
Trifolium nigrescens |
|
---|---|---|
woolly clover |
small white clover |
|
Habit | Herbs annual, 10–20 cm, glabrous or sparsely hairy. | Herbs annual, 10–60 cm, glabrous or glabrescent. |
Stems | prostrate, ascending, or erect, branched. |
usually erect or ascending, rarely prostrate, branched. |
Leaves | palmate; stipules ovate or triangular-lanceolate, 0.4–1.2 cm, margins entire, apex acute or acuminate; petiole 0.5–7 cm; petiolules to 1 mm; leaflets 3, blades obovate, obcordate, or elliptic, 0.4–1.5 × 0.3–1 cm, base cuneate, veins moderately prominent, margins denticulate, apex rounded or emarginate, surfaces sparsely hairy abaxially, glabrous adaxially. |
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, 10–20-flowered, subglobose, soon becoming globose, flowers resupinate, calyces densely white-woolly, compacted, inflated, 0.5–1.5 × 0.5–1.5 cm; involucres a narrow rim, 0.2 mm. |
axillary or terminal, 15–50-flowered, globose, 1–1.8 × 1–1.8 cm; involucres a narrow rim, to 0.2 mm. |
Peduncles | 0.5–1.5 cm. |
1.5–4 cm. |
Pedicels | slightly reflexed, to 0.5 mm; bracteoles cup-shaped, membranous, 0.2 mm. |
reflexed in fruit, 3–6 mm; bracteoles narrowly oblanceolate, 3–6.5 mm. |
Flowers | 3–7 mm; calyx tubular, inflated in fruit, markedly asymmetric-bilabiate, 2–6 mm, woolly adaxially, veins 5–10, connected by lateral veins, tube 1.5–2.5 mm, 4–5 mm in fruit, lobes unequal, subulate, shorter than tube, adaxial spreading or curved, orifice open, abruptly constricted in fruit; corolla pink, 3–6 mm, banner ovate, 3–6 × 3–6 mm, apex emarginate to crenulate. |
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 | ovoid to globose, 2–3 mm. |
linear-oblong, 3–4.5 mm. |
Seeds | 1 or 2, yellow to brown, mottled, mitten-shaped, 0.9–1.1 mm, smooth, glossy. |
1–5, yellow or pale or dark brown, oblong, 1 mm, smooth. |
2n | = 16. |
= 16. |
Trifolium tomentosum |
Trifolium nigrescens |
|
Phenology | Flowering Feb–Apr. | Flowering Mar–Oct. |
Habitat | Sandy lawns, fields, meadows, roadsides, clay soils among vernal pools. | Roadsides, lawns, fields, waste places. |
Elevation | 0–400 m. (0–1300 ft.) | 0–200 m. (0–700 ft.) |
Distribution |
CA; FL; MA; NC; SC; s Europe (Mediterranean); sw Asia; n Africa; Atlantic Islands (Azores) [Introduced in North America; introduced also in South America (Chile), s Africa, Pacific Islands (New Zealand), Australia]
|
AL; FL; GA; LA; MS; TN; TX; s Europe; w Asia; n Africa [Introduced in North America] |
Discussion | Trifolium tomentosum is occasionally cultivated as a forage crop (F. J. Hermann 1953) and is becoming weedy in the flora area and in Australia (R. P. Randall 2002). (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 | ||
Name authority | Linnaeus: Sp. Pl. 2: 771. (1753) | Viviani: Fl. Ital. Fragm., 12, plate 13. (1808) |
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