Trifolium amoenum |
Trifolium carolinianum |
|
---|---|---|
showy Indian clover, two-fork clover |
Carolina clover |
|
Habit | Herbs annual, 45–65 cm, canescent. | Herbs annual, 5–30 cm, pilose. |
Stems | erect, branched from base and distally, or unbranched. |
prostrate, ascending, or erect, branched. |
Leaves | palmate; stipules ovate-oblong, 0.5–1.8 cm, margins entire, toothed, or irregularly lobed, apex acuminate; petiole 0.5–10 cm; petiolules to 1 mm; leaflets 3, blades broadly obovate or elliptic, 1.7–3.3 × 1.1–2 cm, base cuneate, veins fine, margins entire or denticulate, apex rounded, obtuse, or retuse, surfaces pilose, abaxial less so. |
palmate; stipules ovate, 0.6–1 cm, margins entire or serrate, apex acuminate; petiole 2–5 cm; petiolules 1 mm; leaflets 3, blades obovate, 0.6–1.4 × 0.3–1.1 cm, base cuneate, veins moderately thickened, margins denticulate, apex rounded, sometimes retuse, surfaces glabrous except on veins abaxially. |
Inflorescences | terminal or axillary, 30–50-flowered, bluntly conic, ellipsoid, globose, or subglobose, 1.5–3 × 1.5–2.5 cm; involucres absent. |
axillary or terminal, 5–40-flowered, globose, 1–2 × 1–2 cm; involucres minute. |
Peduncles | 5–15 cm. |
± geniculate proximal to flowers, inflorescence appearing sideways or inverted, 3.5–10 cm. |
Pedicels | absent; bracteoles cuplike, to 0.5 mm. |
reflexed, 2–3 mm; bracteoles ovate or lanceolate, 0.5 mm. |
Flowers | 13–16 mm; calyx tubular, 9–12 mm, pubescent, veins 20–30, tube 3 mm, lobes nearly equal, appearing rigidly erect, linear-setaceous, plumose, sinuses acute, orifice open; corolla white to pink with purple tips, 12–16 mm, banner ovate-oblong, 12–15 × 4 mm, apex broadly rounded, emarginate. |
4.5–7 mm; calyx usually pink to magenta, campanulate, bilabiate, 3–4 mm, pilose, veins 5, slightly branched in lobes, tube 0.8–1 mm, lobes unequal, abaxial 3 lanceolate or linear, 0.8–1 mm, villous, adaxial 2 broadly triangular, 2.5–3 mm, orifice open; corolla creamy white, often pink-tinged, darkening in age, 4–4.5 mm, banner broadly ovate-rhombic, 4–4.5 × 3.8–4 mm, apex rounded, slightly erose. |
Legumes | obovoid, 4 mm. |
oblong, 3–4 mm. |
Seeds | 1, dark brown, ellipsoid, 2–3 mm, smooth. |
2–4, yellow-brown to brown, globose to mitten-shaped, 1.1–1.6 mm, rugose. |
2n | = 16. |
|
Trifolium amoenum |
Trifolium carolinianum |
|
Phenology | Flowering Apr–May. | Flowering Apr–Jun. |
Habitat | Grassy slopes, swales, clay soils. | Sandy soils in dry fields, lawns, open woods, disturbed ground, rocky slopes. |
Elevation | 0–100 m. (0–300 ft.) | 0–400 m. (0–1300 ft.) |
Distribution |
CA
|
AL; AR; DE; FL; GA; KS; LA; MO; MS; NC; OK; PA; SC; TX; VA
|
Discussion | Trifolium amoenum was considered extinct (J. P. Smith Jr. 1984) but was rediscovered in 1993 (P. G. Connors 1994). Specimens of T. amoenum are known from Marin, Napa, San Mateo, Solano, and Sonoma counties; it appears to be extant in only single populations in each of Marin and Solano counties. Allozyme studies of the two known populations revealed fixed genetic differences between them (E. E. Knapp and Connors 1999). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Trifolium arvense Walter (1788), a later homonym of T. arvense Linnaeus (1753), was considered a synonym of T. carolinianum by M. Zohary and D. Heller (1984). Trifolium repens Walter (1788, not Linnaeus 1753) is likely also a synonym of T. carolinianum. The record of the species from Vermont is a waif. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Amoria caroliniana, T. oxypetalum, T. umbellatum | |
Name authority | Greene: Fl. Francisc., 27. (1891) | Michaux: Fl. Bor.-Amer. 2: 58. (1803) |
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