Trifolium macrocephalum |
Trifolium gracilentum |
|
---|---|---|
big-head clover, large-head clover |
pin point clover, slender clover |
|
Habit | Herbs perennial, 5–25 cm, villous. | Herbs annual, 2–60 cm, glabrous. |
Stems | erect or ascending, branched. |
erect or ascending, branched. |
Leaves | palmate; stipules ovate, obovate, or oblong, 1–3 cm, margins entire, irregularly lobed, or serrate, apex acute or acuminate; petiole 1–14 cm; petiolules 0.9–1.2 mm; leaflets (5–)7–9, blades broadly to narrowly obovate, often folded, 1–2.7 × 0.4–1.1 cm, base cuneate, veins thickened, especially distally, margins serrulate, apex rounded or truncate, apiculate, surfaces villous abaxially, sparsely villous to glabrate adaxially. |
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. |
Inflorescences | terminal, 20–32-flowered, globose or ovoid-ellipsoid, 2.5–8 × 3–7 cm; involucres absent. |
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. |
Peduncles | 2–8 cm. |
1–9 cm. |
Pedicels | erect, 1–1.5 mm; bracteoles broadly ovate, membranous, to 0.5 mm, truncate. |
becoming dramatically reflexed, 3–4 mm; bracteoles low, cuplike, membranous, to 0.5 mm. |
Flowers | 20–30 mm; calyx campanulate, 10–22 mm, villous, veins 10–15, tube 2.5–4 mm, lobes subequal, subulate, plumose, orifice open; corolla white, creamy white, or pinkish, keel petals deep pink, 20–28 mm, banner ovate or oblong, 20–28 × 10–13 mm, apex rounded or slightly emarginate. |
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. |
Legumes | ovoid, 4–5 mm. |
ovoid-ellipsoid, 4–6 mm. |
Seeds | 1 or 2, yellow or reddish, mitten-shaped to ellipsoid, 2.5–3 mm, smooth. |
1 or 2, tan to brown, mitten-shaped, 1.1–1.5 mm, smooth. |
2n | = 32, 48. |
= 16. |
Trifolium macrocephalum |
Trifolium gracilentum |
|
Phenology | Flowering Apr–Jun. | Flowering Mar–Jun. |
Habitat | Rocky places, hard, compacted clay-gumbo, lava beds, sage-covered slopes, full sun. | Open, grassy areas, gravelly ridges, roadsides, adobe slopes, moist places. |
Elevation | 80–2500 m. [260–8200 ft.] | 50–1200 m. [160–3900 ft.] |
Distribution |
CA; ID; NV; OR; WA
|
AZ; CA; NV; OR; WA; Mexico (Baja California)
|
Discussion | Trifolium macrocephalum has the largest inflorescences of any clover. Trifolium megacephalum Nuttall (1818) is an illegitimate replacement name for Lupinaster macrocephalum Pursh. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Lupinaster macrocephalum | T. denudatum, T. exile, T. gracilentum var. exile, T. gracilentum var. inconspicuum, T. gracilentum var. reductum, T. inconspicuum |
Name authority | (Pursh) Poiret in J. Lamarck et al.: Encycl., suppl. 5: 336. (1817) | Torrey & A. Gray: Fl. N. Amer. 1: 316. (1838) |
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