Trifolium campestre |
Trifolium eriocephalum |
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field clover, hop clover, hop trefoil, low hop-clover, pinnate hop clover |
woolly-head clover |
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Habit | Herbs annual, 5–40 cm, slightly villous or glabrous. | Herbs perennial, 12–46 cm, sparsely hairy to densely villous, appressed-pubescent, or glabrate. | ||||||||||||||||||||
Stems | erect to ascending, branched. |
erect or decumbent, branched. |
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Leaves | pinnate; stipules ovate-lanceolate, 0.5–0.8 cm, margins entire, glandular, apex acuminate; petiole 0.3–2 cm; lateral leaflet petiolules 0.5–0.6 mm, terminal leaflet stalk 3–5 mm; leaflets 3, blades rhombic to obovate, 0.4–1.5 × 0.4–0.8 cm, base cuneate, lateral veins prominent, ± parallel, ascending, margins denticulate distally, apex truncate or retuse, surfaces strigose adaxially. |
palmate; stipules lanceolate or ovate, 1–5 cm, margins entire or denticulate, apex acuminate or acute; petiole 1–15 cm; petiolules 1 mm; leaflets 3, blades linear, linear-elliptic, elliptic, lanceolate, lanceolate-oblong, or obovate, 1–5 × 0.4–1.2 cm, base cuneate, veins fine or ± thickened, margins denticulate or serrulate, apex acuminate or acute, surfaces appressed-pubescent abaxially, glabrous, densely villous, or sparsely or densely pilose adaxially. |
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Inflorescences | axillary, 30–60-flowered, globose or broadly ovoid, 0.8–1.5 × 0.7–1 cm; involucres absent. |
terminal or axillary, 25–70-flowered, inverted or horizontal, ellipsoid or globose to subglobose, 2–3 × 1–3 cm, rachis prolonged beyond flowers; involucres absent. |
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Peduncles | 1.5–3.5 cm. |
bent distally, proximal to flowers, 3–18 cm. |
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Pedicels | reflexed, 0.7–1.2 mm; bracteoles a fringe of red setae. |
reflexed, to 0.3 mm; bracteoles absent. |
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Flowers | 4.3–5 mm; calyx campanulate, strongly bilabiate, 1.3–1.5 mm, glabrous, veins 5, tube 0.3–0.6 mm, lobes unequal, adaxial deltate, very short, lateral and abaxial linear-subulate, each tipped with 1 or 2 stiff hairs, orifice open; corolla yellow becoming brown, 3.5–6 mm, ribbed, banner persistent, obovate, enveloping other petals, boat-shaped, 4.3–5 × 2.8–3.2 mm, apex broad, acute. |
9–18 mm; calyx campanulate, curved in fruit, 4–11 mm, villous, veins 10, tube 1.5–2.5 mm, lobes unequal, 2–3 times tube, subulate, often strongly curved and twisted, plumose, orifice open; corolla white, cream, or purple, 8–16 mm, banner oblanceolate, 8–16 × 3–5 mm, apex rounded or retuse, recurved; ovaries pubescent distally. |
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Legumes | stipitate, oblong, 2–2.5 mm. |
ovoid, 2–3.5 mm. |
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Seeds | 1 or 2, yellow, ellipsoid, 1–1.5 mm, smooth, lustrous. |
(1 or)2–4, yellow-brown to brown, mitten-shaped or subglobose, 1.2–2 mm, smooth. |
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2n | = 14. |
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Trifolium campestre |
Trifolium eriocephalum |
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Phenology | Flowering Jun–Aug. | |||||||||||||||||||||
Habitat | Roadsides, fields. | |||||||||||||||||||||
Elevation | 0–1700 m. (0–5600 ft.) | |||||||||||||||||||||
Distribution |
AK; AL; AR; AZ; CA; 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; NY; OH; OK; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; WY; BC; NB; NF; NS; ON; PE; QC; SPM; Europe; w Asia; n Africa [Introduced in North America; introduced also in South America, e Asia (China), s Africa, Pacific Islands (Hawaii, New Zealand), Australia]
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w United States
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Discussion | Trifolium filiforme Linnaeus and T. procumbens Linnaeus are rejected names that were used historically for T. campestre (J. E. Dandy 1958; N. J. Turland et al. 1996). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Subspecies 6 (6 in the flora). Trifolium eriocephalum was revised by J. M. Gillett (1971). The subspecies exhibit unusually complex distributional patterns, and overlapping morphological features sometimes make identifications problematic (M. Zohary and D. Heller 1984). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 11. | FNA vol. 11. | ||||||||||||||||||||
Parent taxa | Fabaceae > subfam. Faboideae > Trifolium | Fabaceae > subfam. Faboideae > Trifolium | ||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||
Subordinate taxa | ||||||||||||||||||||||
Synonyms | Chrysaspis campestris | |||||||||||||||||||||
Name authority | Schreber in G. F. Hoffmann: Deutschl. Fl. 4: 16, plate 253. (1804) | Nuttall in J. Torrey and A. Gray: Fl. N. Amer. 1: 313. (1838) | ||||||||||||||||||||
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