Trifolium amoenum |
Trifolium rollinsii |
|
---|---|---|
showy Indian clover, two-fork clover |
Rollins' clover |
|
Habit | Herbs annual, 45–65 cm, canescent. | Herbs perennial, 5–20 cm, glabrous. |
Stems | erect, branched from base and distally, or unbranched. |
ascending, cespitose, 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. |
mostly basal, palmate; stipules ovate, 1 cm, margins entire, apex blunt; petiole 2–6 cm; petiolules to 1 mm; leaflets 3, blades obovate or rhombic, 0.6–1.3 × 0.6–1 cm, base cuneate, veins prominent, margins denticulate, apex rounded or retuse, apiculate, surfaces pale abaxially, 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 or axillary, 8–15-flowered, appearing turned to one side, obconic, 1.3–1.8 × 1.1–2.5 cm, rachis prolonged beyond flowers, undivided or forked, often bearing sterile flower buds distally; involucres absent. |
Peduncles | 5–15 cm. |
curved distally proximal to flowers, 3–9 cm. |
Pedicels | absent; bracteoles cuplike, to 0.5 mm. |
reflexed, 1–1.2 mm; bracteoles minute. |
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. |
10–13 mm; calyx purple, campanulate, 5–6 mm, glabrous, veins 10, tube 3.5 mm, lobes equal, subulate, 2 mm, orifice open; corolla purple, often with white tips, 15 mm, banner obovate, 11–13 × 5–6 mm, apex flared. |
Legumes | obovoid, 4 mm. |
not seen. |
Seeds | 1, dark brown, ellipsoid, 2–3 mm, smooth. |
not seen. |
Trifolium amoenum |
Trifolium rollinsii |
|
Phenology | Flowering Apr–May. | Flowering Jun–Aug. |
Habitat | Grassy slopes, swales, clay soils. | Wind-swept alpine areas. |
Elevation | 0–100 m. (0–300 ft.) | 3000–3100 m. (9800–10200 ft.) |
Distribution |
CA
|
NV |
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 rollinsii is known from the Toiyabe Range in Lander and Nye counties in central Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | T. kingii subsp. rollinsii, T. macilentum var. rollinsii | |
Name authority | Greene: Fl. Francisc., 27. (1891) | J. M. Gillett: Madroño 21: 453, fig. 2. (1972) |
Web links |