Trifolium douglasii |
Trifolium polyodon |
|
---|---|---|
Douglas' clover |
Pacific grove clover, woods or Pacific grove clover |
|
Habit | Herbs perennial, 20–75 cm, glabrous or slightly pilose. | Herbs annual, 10–60 cm, glabrous. |
Stems | erect, unbranched or sparsely branched. |
decumbent or ascending, branched. |
Leaves | 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. |
palmate; stipules lanceolate to ovate, 0.4–1.8 cm, margins lacerate, apex acute to acuminate; petiole 0.5–6 cm; petiolules to 1 mm; leaflets 3, blades broadly elliptic to broadly obovate, 0.4–2.5 × 0.4–1.5 cm, base cuneate, veins moderately thickened, margins dentate-serrulate, apex rounded or truncate, often retuse, surfaces glabrous. |
Inflorescences | terminal or axillary, 30–50+-flowered, umbellate, globose to ovoid, 1.5–5 × 2–3.5 cm; involucres absent. |
axillary, 10–25-flowered, subglobose or globose, 1–1.8 × 1–1.8 cm; involucres flattened or bowl-shaped, 4–7 mm, incised 1/2 their length, when folded, not hiding flowers except proximally, lobes 5–12, dentate-lacerate, spinulose. |
Peduncles | 3–12 cm. |
1–2 cm. |
Pedicels | erect or slightly reflexed, to 0.2 mm; bracteoles minute. |
straight, to 1 mm; bracteoles absent. |
Flowers | 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. |
8–10 mm; calyx campanulate-tubular, not slit between adaxial lobes, 5–7 mm, glabrous, veins 20, tube 1.9–2.4 mm, lobes unequal, 3-fid or laciniate, often appearing 7+-lobed, orifice open; corolla pink or pale purple, 8–9 mm, banner elliptic, 8–9 × 2–3 mm, apex retuse. |
Legumes | ovoid, 3–4.5 mm. |
ellipsoid, 3.5–4 mm. |
Seeds | 1 or 2, tan to brown, ovoid, 1–1.5 mm, slightly roughened. |
2, dark brown, mottled, ovoid or reniform, 1.7–1.9 mm, smooth. |
2n | = 16. |
|
Trifolium douglasii |
Trifolium polyodon |
|
Phenology | Flowering Jun–Jul. | Flowering Apr–Jun. |
Habitat | Moist meadows, rich soils in prairies, stream bottoms and banks, openings in pine forests. | Along streams, moist meadows. |
Elevation | 600–1500 m. (2000–4900 ft.) | 0–150 m. (0–500 ft.) |
Distribution |
ID; OR; WA
|
CA |
Discussion | 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.) |
The taxonomic status of Trifolium polyodon, known only from Monterey County, has long been debated. W. L. Jepson (1936) considered it a variety of T. tridentatum Lindley (= T. willdenovii). The first to consider it as a variety of T. variegatum was J. S. Martin (1943), who never formally published a new combination; an invalid combination was made by M. Zohary and D. Heller (1984). D. Isely (1998) included it in his interpretation of T. variegatum as phase 5 of that species; he speculated that T. polyodon might have originated as a hybrid of T. variegatum and T. willdenovii. Molecular studies (N. W. Ellison et al. 2006) showed that T. polyodon is closely related to T. variegatum but is distinct; it also appears to be related to T. cyathiferum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | Fabaceae > subfam. Faboideae > Trifolium | Fabaceae > subfam. Faboideae > Trifolium |
Sibling taxa | ||
Synonyms | T. altissimum | T. tridentatum var. polyodon |
Name authority | House: Bot. Gaz. 41: 335. (1906) | Greene: Pittonia 3: 215. (1897) |
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