Trifolium macrocephalum |
Trifolium bifidum |
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big-head clover, large-head clover |
notch-leaf clover, Pinole clover, piñole clover |
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Habit | Herbs perennial, 5–25 cm, villous. | Herbs annual, 5–55 cm, sparsely pubescent or glabrous. |
Stems | erect or ascending, branched. |
erect, 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 to lanceolate, 0.8–1.5 cm, margins entire or slightly serrate, apex acicular; petiole 1–7 cm; petiolules to 0.5 mm; leaflets 3, blades narrowly obcordate, obovate, oblanceolate, or linear, 1–2.5 × 0.3–0.7 cm, base cuneate, veins moderately thickened, margins serrate distally or entire, apex rounded, truncate, shallowly to deeply retuse, or deeply 2-fid, surfaces glabrous or hairy abaxially along midvein. |
Inflorescences | terminal, 20–32-flowered, globose or ovoid-ellipsoid, 2.5–8 × 3–7 cm; involucres absent. |
axillary or terminal, 5–30-flowered, globose to subglobose, 0.8–1.5 × 0.8–1.5 cm, rachis prolonged beyond flowers; involucres a very narrow rim, to 0.5 mm. |
Peduncles | 2–8 cm. |
3–8 cm. |
Pedicels | erect, 1–1.5 mm; bracteoles broadly ovate, membranous, to 0.5 mm, truncate. |
reflexed in fruit, 1–3 mm; bracteoles broadly triangular, 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. |
6–8 mm; calyx campanulate, 3–3.6 mm, slightly hairy or glabrous, veins 10, tube 1–1.5 mm, lobes unequal, subulate, margins green or purple, orifice open; corolla pink or purple, 5–7 mm, banner elliptic to oblong, 5–7 × 3–4 mm, apex rounded, apiculate. |
Legumes | ovoid, 4–5 mm. |
stipitate, obovoid, 3–4 mm. |
Seeds | 1 or 2, yellow or reddish, mitten-shaped to ellipsoid, 2.5–3 mm, smooth. |
1 or 2, brown, mottled, oblong, 2–3 mm, smooth. |
2n | = 32, 48. |
= 16. |
Trifolium macrocephalum |
Trifolium bifidum |
|
Phenology | Flowering Apr–Jun. | Flowering Apr–Jun. |
Habitat | Rocky places, hard, compacted clay-gumbo, lava beds, sage-covered slopes, full sun. | Open woodlands, fields, roadsides, slopes, stream margins, meadows. |
Elevation | 80–2500 m. [260–8200 ft.] | 0–1200 m. [0–3900 ft.] |
Distribution |
CA; ID; NV; OR; WA
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CA; OR; WA; BC; Mexico (Baja California)
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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.) |
Trifolium bifidum ranges from Baja California, Mexico, northward through California to scattered sites in Oregon, Washington, and British Columbia. Recent re-evaluation of Trifolium bifidum and related species showed complete overlap in characters for the two varieties that have been recognized previously, with no clear distinctions between them (L. Rogers, pers. comm.). (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. bifidum var. decipiens, T. greenei, T. hallii |
Name authority | (Pursh) Poiret in J. Lamarck et al.: Encycl., suppl. 5: 336. (1817) | A. Gray: Proc. Calif. Acad. Sci. 3: 102. (1864) |
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