Trifolium willdenovii |
Trifolium obtusiflorum |
|
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sand clover, thimble clover, tomcat clover, Willdenow's clover |
clammy clover, creek clover |
|
Habit | Herbs annual, 10–60 cm, glabrous. | Herbs annual, 2–100 cm, resinous stipitate-glandular. |
Stems | erect, branched. |
erect or ascending, branched. |
Leaves | palmate; stipules lanceolate or ovate, 1–2 cm, margins dentate or lacerate, apex acuminate; petiole 1–8 cm; petiolules 0.5 mm; leaflets 3, blades linear, lanceolate, or elliptic, 1–5 × 0.2–1.5 cm, base cuneate, veins fine, margins serrate, apex acute, blunt, or retuse, surfaces glabrous. |
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 | axillary or terminal, 10–50-flowered, globose or ovoid, 1–3.5 × 1–3 cm; involucres flattened or bowl-shaped, 3–9 mm, when folded, not hiding flowers except proximally, incised 1/4–1/3 their length. |
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 | 2–15 cm. |
3–15 cm, glandular. |
Pedicels | erect, 0.5 mm; bracteoles absent. |
erect, 1 mm; bracteoles absent. |
Flowers | 12–20 mm; calyx tubular-campanulate, slit between adaxial lobes, 6–9 mm, glabrous, veins 10–15, tube 3–7 mm, lobes unequal, triangular or subulate, usually 3-fid or shouldered below apex, orifice open; corolla usually white with purple spot, sometimes lavender or pink or all white, 10–18 mm, banner narrowly oblong, 12–20 × 3–4 mm, apex obtuse or retuse. |
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 | ellipsoid, 3 mm. |
obovoid, 3.5–4 mm. |
Seeds | 1 or 2, yellow, mottled, globose-ellipsoid, 1.5–2.5 mm, smooth. |
1 or 2, brown, mottled, ellipsoid or mitten-shaped, 2.5 mm, smooth. |
2n | = 16. |
= 16. |
Trifolium willdenovii |
Trifolium obtusiflorum |
|
Phenology | Flowering Mar–Jul. | Flowering Apr–Jul. |
Habitat | Roadsides, meadows, lawns, hillsides, stream margins, open oak chaparral. | Moist swales, creek bottoms. |
Elevation | 0–2500 m. (0–8200 ft.) | 0–1600 m. (0–5200 ft.) |
Distribution |
AZ; CA; ID; OR; WA; BC; Mexico (Baja California)
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CA; OR; Mexico (Baja California, Sinaloa)
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Discussion | Trifolium willdenovii was described by M. Zohary and D. Heller (1984) as one of the most variable clover species in North America. (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 | Fabaceae > subfam. Faboideae > Trifolium | Fabaceae > subfam. Faboideae > Trifolium |
Sibling taxa | ||
Synonyms | T. involucratum, T. aciculare, T. nuttallii, T. scabrellum, T. segetum, T. tridentatum, T. tridentatum var. aciculare, T. tridentatum var. scabrellum, T. tridentatum var. segetum, T. tridentatum var. watsonii, T. trimorphum, T. watsonii | T. majus, T. roscidum, T. tridentatum var. obtusiflorum |
Name authority | Sprengel: Syst. Veg. 3: 208. (1826) | Hooker: Bot. Beechey Voy., 331. (1838) |
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