Trifolium campestre |
Trifolium monanthum |
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field clover, hop clover, hop trefoil, low hop-clover, pinnate hop clover |
carpet clover, mountain carpet clover |
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Habit | Herbs annual, 5–40 cm, slightly villous or glabrous. | Herbs perennial, 3–22 cm, glabrous or hairy, often mat-forming. | ||||||||||||
Stems | erect to ascending, branched. |
decumbent to ascending, much-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 ovate to lanceolate, 0.3–1.2 cm, margins entire, serrate, or slightly lacerate, apex acute to acuminate; petiole 1–4.5 cm; petiolules 0.1–0.5 mm; leaflets 3, blades obovate, oblanceolate, or elliptic, 0.3–2 × 0.2–0.5 cm, base cuneate, veins prominent, margins ± dentate, serrate, or setose, apex acute, rounded, or retuse, surfaces glabrous or slightly villous. |
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Inflorescences | axillary, 30–60-flowered, globose or broadly ovoid, 0.8–1.5 × 0.7–1 cm; involucres absent. |
axillary or terminal, 1–9-flowered, solitary or subglobose, 1–1.6 × 0.3–1.2 cm; involucres campanulate, 2–5 mm, incised nearly to base, lobes 2–8, lanceolate. |
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Peduncles | 1.5–3.5 cm. |
0.5–2 cm. |
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Pedicels | reflexed, 0.7–1.2 mm; bracteoles a fringe of red setae. |
erect, 1 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. |
10–16 mm; calyx tubular, 2–10 mm, glabrous or pubescent, veins 10, tube 4–7 mm, lobes equal, triangular-subulate, orifice open; corolla white, pink, or lavender, keel petals usually purple-spotted, 8–16 mm, banner oblong, 8–13 × 2–5 mm, apex emarginate. |
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Legumes | stipitate, oblong, 2–2.5 mm. |
oblong, 2–4 mm. |
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Seeds | 1 or 2, yellow, ellipsoid, 1–1.5 mm, smooth, lustrous. |
1 or 2, brown, mottled, mitten-shaped, 1–2 mm, dull. |
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2n | = 14. |
= 16. |
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Trifolium campestre |
Trifolium monanthum |
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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; nw Mexico
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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 4 (4 in the flora). Morphological intergradation among subspecies of Trifolium monanthum may be indicative of low genetic barriers to crossing. It might be just as plausible to divide T. mononathum into two species instead of four subspecies (J. M. Gillett 1980), with T. monanthum encompassing populations with white rhizomes, and T. multicaule encompassing populations with taproots. Trifolium monanthum often forms dense mats. (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) | A. Gray: Proc. Amer. Acad. Arts 6: 523. (1865) | ||||||||||||
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