Trifolium amoenum |
Trifolium plumosum |
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showy Indian clover, two-fork clover |
plumed clover |
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Habit | Herbs annual, 45–65 cm, canescent. | Herbs perennial, 10–60 cm, villous. | ||||
Stems | erect, branched from base and distally, or unbranched. |
erect, branched or unbranched. |
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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 linear, oblong, or ovate, 1.5–2.5 cm, margins entire or slightly serrulate, apex acute to acuminate; petiole 1–20 cm; petiolules to 0.5 mm; leaflets 3, blades linear, elliptic, oblong, or lanceolate-elliptic, often folded, falcate, 4–11 × 0.1–1.6 cm, base cuneate, veins thickened, margins denticulate, apex acute or acuminate, surfaces villous. |
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Inflorescences | terminal or axillary, 30–50-flowered, bluntly conic, ellipsoid, globose, or subglobose, 1.5–3 × 1.5–2.5 cm; involucres absent. |
terminal, 70–80-flowered, spicate, ovoid to cylindric, 3–6 × 2.5–3 cm; involucres absent. |
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Peduncles | 5–15 cm. |
2–6 cm. |
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Pedicels | absent; bracteoles cuplike, to 0.5 mm. |
erect or absent, 0–0.5 mm; bracteoles absent. |
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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. |
17–18 mm; calyx campanulate, 5 mm, villous, veins 20, tube 2.5 mm, lobes subequal, subulate, straight, orifice open; corolla creamy white, keel petals crimson, 12–22 mm, banner oblong, 12–22 × 3–5 mm, apex acute; ovaries glabrous or pubescent distally. |
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Legumes | obovoid, 4 mm. |
obovoid, 4–5 mm. |
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Seeds | 1, dark brown, ellipsoid, 2–3 mm, smooth. |
1–3, reddish brown or tan, ellipsoid, 1.8–2 mm, smooth, glossy. |
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2n | = 32. |
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Trifolium amoenum |
Trifolium plumosum |
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Phenology | Flowering Apr–May. | |||||
Habitat | Grassy slopes, swales, clay soils. | |||||
Elevation | 0–100 m. (0–300 ft.) | |||||
Distribution |
CA
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nw United States
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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.) |
Subspecies 2 (2 in the flora). J. M. Gillett (1972) stated that the leaflet width in the basal leaves is the best distinction between the two subspecies, which are geographically isolated. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 11. | FNA vol. 11. | ||||
Parent taxa | ||||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | Greene: Fl. Francisc., 27. (1891) | Douglas in W. J. Hooker: Fl. Bor.-Amer. 1: 130, plate 49. (1831) | ||||
Web links |