Trifolium bifidum |
Trifolium pratense |
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notch-leaf clover, Pinole clover, piñole clover |
red clover |
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Habit | Herbs annual, 5–55 cm, sparsely pubescent or glabrous. | Herbs perennial, 20–70 cm, pilose or glabrous. |
Stems | erect, branched. |
erect, ascending, or decumbent, branched. |
Leaves | 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. |
palmate; stipules broadly triangular, 1–2 cm, margins entire, sometimes ciliate, apex mucronate or setaceous; petiole 1–9 cm; petiolules 1 mm; leaflets 3, blades elliptic to obovate, 1.5–5 × 0.7–1.5 cm, base cuneate, veins prominent, margins subentire, apex obtuse, acute, or retuse, surfaces appressed-pubescent. |
Inflorescences | 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. |
terminal, solitary or paired, 75–100+-flowered, globose or ovoid, 1.2–7.7 × 0.7–2.2 cm; involucres absent, involucrelike structures formed of stipules of distalmost leaves. |
Peduncles | 3–8 cm. |
± 0 cm, subtended by stipules of distal leaves. |
Pedicels | reflexed in fruit, 1–3 mm; bracteoles broadly triangular, membranous, to 0.5 mm. |
straight, 0–1 mm; bracteoles absent. |
Flowers | 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. |
15–18 mm; calyx tubular-campanulate, 8–11 mm, hairy, veins 10, tube 3–4 mm, lobes unequal, adaxial equaling tube, lateral and abaxial 2 times tube, orifice hairy, slightly closed; corolla usually rose-purple, rarely pink or white, 13–18 mm, banner elliptic-ovate, 10–13 × 3–5 mm, apex narrowly rounded. |
Legumes | stipitate, obovoid, 3–4 mm. |
oblong, leathery distally, transversely dehiscent, 3 mm. |
Seeds | 1 or 2, brown, mottled, oblong, 2–3 mm, smooth. |
1 or 2, yellow, yellow-brown, or purple, ovoid, 1.6–2 mm, smooth, dull. |
2n | = 16. |
= 14. |
Trifolium bifidum |
Trifolium pratense |
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Phenology | Flowering Apr–Jun. | Flowering May–Sep. |
Habitat | Open woodlands, fields, roadsides, slopes, stream margins, meadows. | Fields, prairies, roadsides, disturbed areas. |
Elevation | 0–1200 m. (0–3900 ft.) | 0–3100 m. (0–10200 ft.) |
Distribution |
CA; OR; WA; BC; Mexico (Baja California)
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AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; SPM; Greenland; Eurasia [Introduced in North America; introduced also in s South America, s Africa, Pacific Islands (Hawaii, New Zealand), Australia]
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Discussion | 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.) |
Trifolium pratense is morphologically variable and numerous varieties have been recognized (M. Zohary and D. Heller 1984). Distinctions among these are slight and intergradation is common, perhaps due to the long-time cultivation of the species. In North America, the following varieties are sometimes recognized: var. pratense with stems decumbent to ascending, 20–40 cm, with dense, appressed, white hairs; var. sativum Schreber with stems mostly erect, 40–100 cm, sparsely hairy or glabrous; and var. americanum Harz with stems 30–100 cm, with dense, spreading hairs. (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. bifidum var. decipiens, T. greenei, T. hallii | T. pensylvanicum |
Name authority | A. Gray: Proc. Calif. Acad. Sci. 3: 102. (1864) | Linnaeus: Sp. Pl. 2: 768. (1753) |
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