Trifolium macrocephalum |
Trifolium obtusiflorum |
|
---|---|---|
big-head clover, large-head clover |
clammy clover, creek clover |
|
Habit | Herbs perennial, 5–25 cm, villous. | Herbs annual, 2–100 cm, resinous stipitate-glandular. |
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, 1–1.5 cm, sheathing, margins deeply lacerate, apex acuminate; petiole 1.5–10 cm; petiolules to 0.5 mm; leaflets 3, blades elliptic, lanceolate, oblanceolate, rhombic, or obovate, 1.5–4 × 0.3–1.7 cm, base cuneate, veins thickened, margins coarsely spinulose-serrate, apex acute, mucronate, surfaces glandular. |
Inflorescences | terminal, 20–32-flowered, globose or ovoid-ellipsoid, 2.5–8 × 3–7 cm; involucres absent. |
axillary or terminal, 10–50-flowered, globose or ovoid, 1–3.5 × 1–3 cm; involucres flattened or bowl-shaped, 3–8 mm, when folded, not hiding flowers except proximally, incised 1/4–1/3 their length. |
Peduncles | 2–8 cm. |
3–15 cm, glandular. |
Pedicels | erect, 1–1.5 mm; bracteoles broadly ovate, membranous, to 0.5 mm, truncate. |
erect, 1 mm; bracteoles absent. |
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. |
13–20 mm; calyx tubular-campanulate, slit between adaxial lobes, 10–13 mm, glandular, veins 20+, tube 5–7 mm, lobes unequal, narrowly triangular or lanceolate-subulate, usually entire, rarely 3-fid or shouldered below apex, orifice open; corolla white or pale pinkish with dark purple spot, 10–18 mm, banner broadly elliptic, 10–18 × 2–4 mm, apex blunt. |
Legumes | ovoid, 4–5 mm. |
obovoid, 3.5–4 mm. |
Seeds | 1 or 2, yellow or reddish, mitten-shaped to ellipsoid, 2.5–3 mm, smooth. |
1 or 2, brown, mottled, ellipsoid or mitten-shaped, 2.5 mm, smooth. |
2n | = 32, 48. |
= 16. |
Trifolium macrocephalum |
Trifolium obtusiflorum |
|
Phenology | Flowering Apr–Jun. | Flowering Apr–Jul. |
Habitat | Rocky places, hard, compacted clay-gumbo, lava beds, sage-covered slopes, full sun. | Moist swales, creek bottoms. |
Elevation | 80–2500 m. [260–8200 ft.] | 0–1600 m. [0–5200 ft.] |
Distribution |
CA; ID; NV; OR; WA
|
CA; OR; Mexico (Baja California, Sinaloa)
|
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 obtusiflorum is much less common than the similar T. willdenovii, occurring in moist areas in cismontane California and north into Oregon (W. L. Jepson [1923–1925]). It is easy to distinguish from T. willdenovii by its glandularity, which causes fresh specimens to be sticky to the touch. (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. majus, T. roscidum, T. tridentatum var. obtusiflorum |
Name authority | (Pursh) Poiret in J. Lamarck et al.: Encycl., suppl. 5: 336. (1817) | Hooker: Bot. Beechey Voy., 331. (1838) |
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