Trifolium amoenum |
Trifolium andinum |
|
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showy Indian clover, two-fork clover |
Great Divide clover, intermountain clover |
|
Habit | Herbs annual, 45–65 cm, canescent. | Herbs perennial, 5–15 cm, pubescent. |
Stems | erect, branched from base and distally, or unbranched. |
erect or ascending, cespitose, much-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 oblanceolate, 0.5–1.4 cm, margins entire, apex acute-acuminate; petiole 0.5–4 cm; petiolules to 0.1 mm; leaflets 3, blades oblanceolate, often folded, 0.4–1.5 × 0.2–0.4 cm, base cuneate, veins obscure, margins subentire to denticulate distally, apex acute, mucronulate, surfaces villous. |
Inflorescences | terminal or axillary, 30–50-flowered, bluntly conic, ellipsoid, globose, or subglobose, 1.5–3 × 1.5–2.5 cm; involucres absent. |
terminal, usually formed of 2 sessile heads, 15–25-flowered, globose, 0.8–2 × 0.6–1.5 cm; involucres absent, distal stipules and leaves sometimes forming involucrelike structure. |
Peduncles | 5–15 cm. |
between distal leaves or involucrelike structure and inflorescences 0.5–6 cm. |
Pedicels | absent; bracteoles cuplike, to 0.5 mm. |
straight, (0–)1–2 mm; bracteoles broadly ovate, truncate, membranous, to 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. |
10–15 mm; calyx tubular-campanulate, 6–9 mm, rough-hairy or glabrous, veins 10, tube 3–6 mm, lobes subequal, subulate, orifice open; corolla light purple, 10–15 mm, banner oblong, 9–13 × 3–4 mm, apex rounded or truncate; ovaries pubescent distally. |
Legumes | obovoid, 4 mm. |
ellipsoid, 4–5 mm. |
Seeds | 1, dark brown, ellipsoid, 2–3 mm, smooth. |
1 or 2, brown, ovoid, 1.5–2 mm, smooth. |
Trifolium amoenum |
Trifolium andinum |
|
Phenology | Flowering Apr–May. | Flowering May–Jun. |
Habitat | Grassy slopes, swales, clay soils. | Shale or clay bluffs and hilltops, crevices of volcanic or limestone rock, pinyon-juniper belt. |
Elevation | 0–100 m. (0–300 ft.) | 1600–2300 m. (5200–7500 ft.) |
Distribution |
CA
|
AZ; CO; NM; NV; UT; 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 andinum ranges from central and southern Nevada into west-central Utah, north-central Arizona to southeastern Utah, north-central New Mexico, and northeastern Utah into southwestern Wyoming. Differentiation of T. andinum into subspecific taxa proved impossible, since no consistent gaps in morphological traits could be found. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | T. andinum var. canone, T. andinum var. navajoense, T. andinum var. podocephalum, T. andinum var. wahwahense | |
Name authority | Greene: Fl. Francisc., 27. (1891) | Nuttall in J. Torrey and A. Gray: Fl. N. Amer. 1: 314. (1838) |
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