Trifolium amoenum |
Trifolium barnebyi |
|
---|---|---|
showy Indian clover, two-fork clover |
Barneby's clover |
|
Habit | Herbs annual, 45–65 cm, canescent. | Herbs perennial, 3–5 cm, mostly glabrous. |
Stems | erect, branched from base and distally, or unbranched. |
densely mat-forming, short-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 or lanceolate, 0.5–1 cm, margins entire or lobed, apex acute or acuminate; petiole 0.3–30 cm, pubescent; petiolules 0.2 mm; leaflets 3, blades oblanceolate, 0.3–1.6 × 0.1–0.7 cm, base cuneate, veins close-set, 12–18 pairs of primary veins, 0.5 mm apart, margins sharply antrorsely serrate, apex acute, long-apiculate, surfaces usually glabrous, rarely midvein pubescent abaxially. |
Inflorescences | terminal or axillary, 30–50-flowered, bluntly conic, ellipsoid, globose, or subglobose, 1.5–3 × 1.5–2.5 cm; involucres absent. |
terminal, 8–18-flowered, globose or subglobose, 1.2–2.5 × 2–3 cm; involucres absent. |
Peduncles | 5–15 cm. |
0.5–3.5 cm, pubescent. |
Pedicels | absent; bracteoles cuplike, to 0.5 mm. |
reflexed, 2–3.5 mm, pubescent; bracteoles broad, membranous, to 0.2 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. |
8–13 mm; calyx campanulate, 4–6 mm, pubescent, veins 5–10, tube 1.5–2.5 mm, lobes subequal, narrowly triangular-subulate, orifice open; corolla creamy white, 8–13 mm, banner broadly elliptic-oblong, 10–13 × 6–8 mm, apex rounded, slightly apiculate. |
Legumes | obovoid, 4 mm. |
stipitate, flattened, ovoid, 2–3.5 mm. |
Seeds | 1, dark brown, ellipsoid, 2–3 mm, smooth. |
1, yellow, mottled, flattened-ovoid, 2 mm, smooth. |
Trifolium amoenum |
Trifolium barnebyi |
|
Phenology | Flowering Apr–May. | Flowering Jun. |
Habitat | Grassy slopes, swales, clay soils. | Sandstone ledges and outcrops. |
Elevation | 0–100 m. (0–300 ft.) | 1700–2100 m. (5600–6900 ft.) |
Distribution |
CA
|
WY |
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 barnebyi is known from central Wyoming. It was originally described as a variety of T. haydenii, but was elevated to species rank based on its pubescent petioles, pedicels, and peduncles, closely spaced leaflet veins, and more elongate leaflets that are two times as long as wide. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | T. haydenii var. barnebyi | |
Name authority | Greene: Fl. Francisc., 27. (1891) | (Isely) Dorn & Lichvar: Madroño 28: 189. (1981) |
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