Trifolium lappaceum |
Trifolium campestre |
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burdock clover |
field clover, hop clover, hop trefoil, low hop-clover, pinnate hop clover |
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Habit | Herbs annual, 5–60 cm, hirsute or glabrous. | Herbs annual, 5–40 cm, slightly villous or glabrous. |
Stems | erect to decumbent, branched. |
erect to ascending, branched. |
Leaves | palmate; stipules oblong, 0.5–1.9 cm, margins entire, apex lanceolate-subulate; petiole 0.3–5 cm; petiolules 1 mm; leaflets 3, blades ovate to obovate, 0.5–1.5 × 0.3–2 cm, base cuneate, veins fine, margins denticulate to dentate, apex rounded, truncate, or emarginate, surfaces hirsute. |
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. |
Inflorescences | terminal, 40–60-flowered, globose or ovoid, burlike, not disarticulating at maturity, 1–1.4 × 1.8–2 cm; involucres absent. |
axillary, 30–60-flowered, globose or broadly ovoid, 0.8–1.5 × 0.7–1 cm; involucres absent. |
Peduncles | 0.1–0.7 cm. |
1.5–3.5 cm. |
Pedicels | straight, 0.5 mm; bracteoles absent. |
reflexed, 0.7–1.2 mm; bracteoles a fringe of red setae. |
Flowers | 7–9 mm; calyx campanulate, 7–9 mm, glabrous, veins 20, tube 3 mm, lobes equal, longer than tube, setaceous becoming spinose, orifice hairy, open; corolla pinkish white, 6–10 mm, banner elliptic, 6–9 × 1.5–2 mm, apex emarginate. |
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. |
Legumes | ovoid, leathery distally, transversely dehiscent, 1.5 mm, long-beaked. |
stipitate, oblong, 2–2.5 mm. |
Seeds | 1, light brown, reddish, or yellow with reddish spots, ovoid, 1 mm, smooth, shiny. |
1 or 2, yellow, ellipsoid, 1–1.5 mm, smooth, lustrous. |
2n | = 16. |
= 14. |
Trifolium lappaceum |
Trifolium campestre |
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Phenology | Flowering Mar–Jun. | Flowering Jun–Aug. |
Habitat | Fields, roadsides, grassy areas. | Roadsides, fields. |
Elevation | 0–300 m. (0–1000 ft.) | 0–1700 m. (0–5600 ft.) |
Distribution |
AL; FL; LA; MS; NC; NJ; PA; SC; TN; TX; s Europe; w Asia; n Africa; Atlantic Islands (Canary Islands) [Introduced in North America; introduced also in s South America (Uruguay), s Africa, Australia]
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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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Discussion | Trifolium lappaceum was introduced to the United States about 1903; it has been used as a winter annual pasture and hay crop (E. A. Hollowell 1939), as well as in roadside grass plantings as a nitrogen source. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Chrysaspis campestris | |
Name authority | Linnaeus: Sp. Pl. 2: 768. (1753) | Schreber in G. F. Hoffmann: Deutschl. Fl. 4: 16, plate 253. (1804) |
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