Trifolium dubium |
Trifolium bejariense |
|
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least hop clover, lesser hop clover, lesser hop trefoil, little hop clover, shamrock, small hop-clover, suckling clover |
bejar clover |
|
Habit | Herbs annual, 20–40 cm, glabrous or sparsely hairy. | Herbs annual, 5–25 cm, pilose. |
Stems | erect to prostrate, branched from base. |
erect or ascending, branched. |
Leaves | pinnate; stipules ovate, 0.3–0.5 cm, margins entire, apex acute; petiole to 1.5 cm; lateral leaflet petiolules to 0.5 mm, terminal leaflet stalk 1–1.5 mm; leaflets 3, blades obovate to elliptic-lanceolate, 1–2 × 0.5–1.5 cm, base cuneate, lateral veins prominent, ± parallel, ascending, margins dentate distally, apex rounded or retuse, surfaces glabrous or sparsely hairy. |
palmate; stipules oblong to ovate, 0.8–1 cm, margins slightly denticulate or entire, apex acute to acuminate; petiole 1–5 cm; petiolules to 1 mm; leaflets 3, blades obovate, 0.7–1.4 × 0.3–0.8 cm, base broadly cuneate, veins thickened, recurved, margins slightly denticulate, apex rounded or retuse, surfaces pubescent abaxially, glabrous adaxially. |
Inflorescences | axillary or terminal, 5–20-flowered, ovoid or globose, 0.5–0.9 × 0.6 cm; involucres absent. |
axillary or terminal, 5–15-flowered, globose or subglobose, 1–2 × 1.5–2 cm; involucres floral bracts forming a small, scarious involucre. |
Peduncles | 1–1.5 cm. |
geniculate proximal to flowers, inflorescence appearing inverted, 2.5–11 cm. |
Pedicels | reflexed, 0.2–0.5 mm; bracteoles a fringe of red setae. |
curved, 3–4 mm; bracteoles broadly rhombic, membranous, to 0.5 mm, margins dentate. |
Flowers | 2.8–3.5 mm; calyx campanulate, 1.5–2 mm, glabrous, veins 5, tube 0.8–1 mm, lobes unequal, longer than tube, adaxial 2 shorter, orifice open; corolla pale yellow becoming brown, 2.6–3.2 mm, not or slightly ribbed, banner persistent, spatulate, 2.6–3.2 × 2 mm, apex rounded to broadly acute. |
7–9 mm; calyx campanulate, markedly bilabiate, venation strongly reticulate, 5–6 mm, sparsely pilose marginally, veins 5, reticulate in lobes, tube 0.7–1 mm, lobes unequal, abaxial 3 triangular-ovate, 2–3 mm, central abaxial lobe nearly linear, pubescent only along margins, adaxial 2 obovate, 5 mm, orifice open; corolla white, tinged with pink or lavender, darkening in age, 6–8 mm, banner broadly ovate, 6–8 × 5–6 mm, apex rounded, denticulate. |
Legumes | stipitate, ellipsoid, 1.5–2 mm, short beaked. |
oblong-ovoid, 3–4 mm. |
Seeds | 1, yellow or pale brown, ellipsoid, 0.9–1 mm, smooth, glossy. |
2–6, yellow, globose to mitten-shaped, 1.1–1.6 mm, rugose. |
2n | = 16, 28, 32. |
= 16. |
Trifolium dubium |
Trifolium bejariense |
|
Phenology | Flowering May–Oct. | Flowering Mar–May. |
Habitat | Disturbed ground, fields. | Sandy prairies, open woods. |
Elevation | 0–2300 m. (0–7500 ft.) | 0–100 m. (0–300 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; NV; NY; OH; OK; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; WY; BC; NB; NS; ON; PE; QC; SPM; c Europe; s Europe; w Asia [Introduced in North America; introduced also in s South America, e Asia (e China), n, s Africa, Pacific Islands (Hawaii, New Zealand), Australia]
|
AR; LA; TX |
Discussion | Trifolium dubium is often confused with Medicago lupulina Linnaeus; the latter may be distinguished by its toothed stipules, deciduous corollas, and shiny, black fruits. Little hop clover may be the co-called shamrock of Irish folklore (E. C. Nelson 1991; P. S. Wyse Jackson 2014); other candidates include other species of Trifolium or species of Medicago or Oxalis. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Trifolium bejariense ranges in east-central Texas from Hunt and Lamar counties in the north, southward to Fort Bend and Harris counties, and westward to Travis and Wilson counties; the species is also known from Acadia and Rapides parishes in Louisiana, and Nevada County in Arkansas. L. F. McDermott reduced Trifolium bejariense to T. carolinianum forma bejariense (Moricand) McDermott. (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 dubia, T. minus | T. macrocalyx |
Name authority | Sibthorp: Fl. Oxon., 231. (1794) | Moricand: Pl. Nouv. Amér., 2, plate 2. (1834) |
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