Trifolium macrocephalum |
Trifolium douglasii |
|
---|---|---|
big-head clover, large-head clover |
Douglas' clover |
|
Habit | Herbs perennial, 5–25 cm, villous. | Herbs perennial, 20–75 cm, glabrous or slightly pilose. |
Stems | erect or ascending, branched. |
erect, unbranched or sparsely 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 lanceolate to ovate, 1.5–6.5 cm, margins setose-serrulate or entire, apex acuminate; petiole 1.5–15 cm; petiolules 1 mm; leaflets 3, blades elliptic-oblanceolate to linear-elliptic, 3–9.5 × 0.5–1.6 cm, base cuneate, lateral veins prominent, recurved, dichotomously forked near margin, margins setose-denticulate to serrate, apex rounded or acute, surfaces glaucous, glabrous, sometimes sparsely pubescent abaxially. |
Inflorescences | terminal, 20–32-flowered, globose or ovoid-ellipsoid, 2.5–8 × 3–7 cm; involucres absent. |
terminal or axillary, 30–50+-flowered, umbellate, globose to ovoid, 1.5–5 × 2–3.5 cm; involucres absent. |
Peduncles | 2–8 cm. |
3–12 cm. |
Pedicels | erect, 1–1.5 mm; bracteoles broadly ovate, membranous, to 0.5 mm, truncate. |
erect or slightly reflexed, to 0.2 mm; bracteoles minute. |
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. |
14–16 mm; calyx campanulate, 6–9 mm, pilose, veins 15–20, tube 1.5–3 mm, lobes unequal, narrow, triangular or subulate, abaxial lobe straight, lateral and adaxial tortuous, recurved inwards around corolla, orifice open; corolla magenta, 12–16 mm, banner oblong, 12–16 × 4–6 mm, apex flared, acute or obtuse; ovaries glabrous or pubescent distally. |
Legumes | ovoid, 4–5 mm. |
ovoid, 3–4.5 mm. |
Seeds | 1 or 2, yellow or reddish, mitten-shaped to ellipsoid, 2.5–3 mm, smooth. |
1 or 2, tan to brown, ovoid, 1–1.5 mm, slightly roughened. |
2n | = 32, 48. |
= 16. |
Trifolium macrocephalum |
Trifolium douglasii |
|
Phenology | Flowering Apr–Jun. | Flowering Jun–Jul. |
Habitat | Rocky places, hard, compacted clay-gumbo, lava beds, sage-covered slopes, full sun. | Moist meadows, rich soils in prairies, stream bottoms and banks, openings in pine forests. |
Elevation | 80–2500 m. [260–8200 ft.] | 600–1500 m. [2000–4900 ft.] |
Distribution |
CA; ID; NV; OR; WA
|
ID; OR; WA
|
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 douglasii is rare throughout its range and has been impacted by agricultural practices (P. Camp et al. 2011). (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. altissimum |
Name authority | (Pursh) Poiret in J. Lamarck et al.: Encycl., suppl. 5: 336. (1817) | House: Bot. Gaz. 41: 335. (1906) |
Web links |