Trifolium amoenum |
Trifolium owyheense |
|
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showy Indian clover, two-fork clover |
Owyhee clover |
|
Habit | Herbs annual, 45–65 cm, canescent. | Herbs perennial, 10–20 cm, glaucous, glabrous. |
Stems | erect, branched from base and distally, or unbranched. |
cespitose, spreading, branched proximally, sparsely branched distally. |
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 broadly obovate, 1–2 cm, fused at base, margins slightly lobed, apex acute; petiole 2–6 cm; petiolules 1–1.5 mm; leaflets 3, blades ovate, obovate, or orbiculate, slightly overlapping, 1–2 × 0.7–2.3 cm, base truncate to rounded, veins prominent, margins sparsely dentate, apex rounded, emarginate, surfaces glabrous. |
Inflorescences | terminal or axillary, 30–50-flowered, bluntly conic, ellipsoid, globose, or subglobose, 1.5–3 × 1.5–2.5 cm; involucres absent. |
terminal, 20–30-flowered, globose, usually formed of 2 sessile heads, 2.5–5 × 2.5–5 cm; involucres absent. |
Peduncles | 5–15 cm. |
3–7 cm, surpassing subtending leaves. |
Pedicels | absent; bracteoles cuplike, to 0.5 mm. |
erect, reflexed in proximalmost flowers, 1 mm; bracteoles cuplike, 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. |
15–21 mm; calyx tubular-campanulate, 9–12 mm, pilose, veins 10, tube 4.5–6 mm, lobes subequal, abaxialmost longest, subulate, orifice open; corolla deep pink or magenta, 20–23 mm, banner tubular for most their length, 18–22 × 5–7 mm, apex flared. |
Legumes | obovoid, 4 mm. |
ellipsoid, 4–5 mm. |
Seeds | 1, dark brown, ellipsoid, 2–3 mm, smooth. |
1 or 2, yellow-mottled, mitten-shaped, 2–3 mm, smooth. |
Trifolium amoenum |
Trifolium owyheense |
|
Phenology | Flowering Apr–May. | Flowering May–Jun. |
Habitat | Grassy slopes, swales, clay soils. | Dry shale hillsides on diatomaceous earth. |
Elevation | 0–100 m. (0–300 ft.) | 1000–2000 m. (3300–6600 ft.) |
Distribution |
CA
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ID; OR
|
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 owyheense is known from about 40 populations in a small portion of east-central Malheur County in Oregon, and immediately adjacent Owyhee County in Idaho (M. Mancuso 2001). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Greene: Fl. Francisc., 27. (1891) | Gilkey: Madroño 13: 169, fig. 1. (1956) |
Web links |