Trifolium gracilentum |
Trifolium trichocalyx |
|
---|---|---|
pin point clover, slender clover |
Monterey clover |
|
Habit | Herbs annual, 2–60 cm, glabrous. | Herbs annual, 5–45 cm, sparsely villous to glabrescent. |
Stems | erect or ascending, branched. |
prostrate, decumbent, or erect, branched. |
Leaves | palmate; stipules ovate-lanceolate, 0.5–2.5 cm, membranous, margins entire or slightly serrate, apex long-acuminate; petiole 0.5–9 cm; petiolules to 0.5 mm; leaflets 3, blades obovate to obcordate, 0.5–2.5 × 0.2–1.5 cm, base cuneate, veins moderately thickened, margins setose-serrulate, apex rounded, shallowly retuse, surfaces glabrous. |
palmate; stipules ovate, 0.4–1.2 cm, margins serrate-lacerate, apex acuminate; petiole 1–4 cm; petiolules 0.5 mm; leaflets 3, blades obovate, 0.5–1.5 × 0.4–1 cm, base cuneate, veins moderately prominent, margins denticulate, apex truncate, retuse, or mucronulate, surfaces glabrescent. |
Inflorescences | axillary or terminal, 10–25-flowered, globose to subglobose, 0.5–2 × 0.5–2 cm, rachis prolonged beyond flowers; involucres a narrow, membranous, dentate rim, to 0.5 mm. |
axillary or terminal, 2–15-flowered, subglobose, 1.5–1.8 × 0.5–1.5 cm; involucres flattened or vase-shaped, 1–3 mm, when folded, not hiding flowers except proximally, incised 2/3–3/4 their length, lobes 5–15, linear-lanceolate, entire, acuminate. |
Peduncles | 1–9 cm. |
1.5–4 cm. |
Pedicels | becoming dramatically reflexed, 3–4 mm; bracteoles low, cuplike, membranous, to 0.5 mm. |
erect, 1.5 mm; bracteoles absent. |
Flowers | 5–7.5 mm; calyx narrowly campanulate, 4.5–6.5 mm, glabrous, veins 10, tube 2–2.5 mm, lobes unequal, long-triangular, margins green or purple, orifice open; corolla white, pink, or purple, 5–8 mm, banner ovate, 5–8 × 3–4 mm, apex broadly rounded, retuse or apiculate. |
8–11 mm; calyx campanulate-tubular, not slit between adaxial lobes, 6–9 mm, usually densely pubescent, rarely sparsely so, veins 10, tube 2.5–4.5 mm, lobes unequal, lanceolate-subulate, orifice open; corolla light purple with darker purple keel petals, 6–10 mm, banner narrowly obovate, 4–5 × 1 mm, apex retuse. |
Legumes | ovoid-ellipsoid, 4–6 mm. |
sessile, oblong, 5 mm. |
Seeds | 1 or 2, tan to brown, mitten-shaped, 1.1–1.5 mm, smooth. |
3–6(–9), pale brown, mottled purple, globose to mitten-shaped, 0.8–1 mm, smooth to slightly roughened, semiglossy. |
2n | = 16. |
|
Trifolium gracilentum |
Trifolium trichocalyx |
|
Phenology | Flowering Mar–Jun. | Flowering Apr–May. |
Habitat | Open, grassy areas, gravelly ridges, roadsides, adobe slopes, moist places. | Sandy, rich soils in open Monterey pine forests, often after fire. |
Elevation | 50–1200 m. (200–3900 ft.) | 0–50 m. (0–200 ft.) |
Distribution |
AZ; CA; NV; OR; WA; Mexico (Baja California)
|
CA |
Discussion | Abundance of Trifolium gracilentum increases in response to burns (J. M. DiTomaso et al. 1999). The record of Trifolium gracilentum from South Carolina is a waif. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Trifolium trichocalyx is an extremely rare species known only from Mendocino and Monterey counties. D. I. Axelrod (1982) suggested that T. trichocalyx might have originated as a hybrid between T. microcephalum and T. variegatum, but this is not supported by molecular studies (N. W. Ellison et al. 2006). It appears to be fire-adapted and appeared in large numbers shortly after a fire in 1987 (U.S. Fish and Wildlife Service 2004). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | T. denudatum, T. exile, T. gracilentum var. exile, T. gracilentum var. inconspicuum, T. gracilentum var. reductum, T. inconspicuum | T. oliganthum var. trichocalyx |
Name authority | Torrey & A. Gray: Fl. N. Amer. 1: 316. (1838) | A. Heller: Muhlenbergia 1: 55. (1904) |
Web links |