Trifolium campestre |
Trifolium alexandrinum |
|
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field clover, hop clover, hop trefoil, low hop-clover, pinnate hop clover |
Egyptian clover |
|
Habit | Herbs annual, 5–40 cm, slightly villous or glabrous. | Herbs annual, 20–60 cm, appressed-pubescent. |
Stems | erect to ascending, branched. |
erect, branched. |
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, 1–2 cm, margins denticulate distally, plumose-ciliate, apex caudate; petiole 1–8 cm; petiolules 1+ mm; leaflets 3, blades broadly elliptic to oblong, 1–5 × 0.5–1.5 cm, base cuneate, veins fine, margins denticulate, apex usually mucronate, sometimes retuse, surfaces hairy. |
Inflorescences | axillary, 30–60-flowered, globose or broadly ovoid, 0.8–1.5 × 0.7–1 cm; involucres absent. |
terminal, 25–100-flowered, ovoid, elongate in fruit, 1–2.5 × 1–1.5 cm; involucres minute or absent. |
Peduncles | 1.5–3.5 cm. |
0.5–9 cm. |
Pedicels | reflexed, 0.7–1.2 mm; bracteoles a fringe of red setae. |
absent; bracteoles absent. |
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. |
13–16 mm; calyx cylindric (campanulate in fruit), 6–8 mm, appressed-hairy, veins 10, tube 1–2 mm, lobes erect to slightly spreading, equal or abaxial 2 slightly longer, narrowly triangular, orifice open, hairy; corolla cream or yellowish white, 13–16 mm, banner narrowly spatulate, 13–16 × 3–4 mm, apex obtuse. |
Legumes | stipitate, oblong, 2–2.5 mm. |
ellipsoid, leathery distally, transversely dehiscent, 2.2–2.5 mm. |
Seeds | 1 or 2, yellow, ellipsoid, 1–1.5 mm, smooth, lustrous. |
1, yellow, ovoid, 2–2.2 mm, smooth, glossy. |
2n | = 14. |
= 16. |
Trifolium campestre |
Trifolium alexandrinum |
|
Phenology | Flowering Jun–Aug. | Flowering Apr–May. |
Habitat | Roadsides, fields. | Disturbed areas, fields. |
Elevation | 0–1700 m. (0–5600 ft.) | 0–50 m. (0–200 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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CA; w Asia (Syria) [Introduced in North America; introduced also in e Asia (e China), n Africa, Australia] |
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.) |
Trifolium alexandrinum (known also as berseem, from its Arabic name) has been cultivated in the Mediterranean region for millennia and appears to have been introduced into Egypt in the sixth century (P. B. Kennedy and W. W. Mackie 1925). The origin of T. alexandrinum was long shrouded in mystery, because it appeared that the progenitors of the species were possibly extinct (W. E. Knight 1985b). Examination of similar species using molecular data gave indications that T. berytheum Boissier & C. I. Blanche and T. salmoneum Mouterde might be the primary ancestors from which domestication occurred through artificial selection in Syria (A. Badr et al. 2008). (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 | Chrysaspis campestris | |
Name authority | Schreber in G. F. Hoffmann: Deutschl. Fl. 4: 16, plate 253. (1804) | Linnaeus: Cent. Pl. I, 25. (1755) |
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