Trifolium macraei |
Trifolium microcephalum |
|
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Chilean clover, Macrae's clover |
small-head clover |
|
Habit | Herbs annual, 3–30 cm, pubescent. | Herbs annual, 3–55 cm, densely to sparsely pubescent. |
Stems | erect, ascending, or prostrate, branched. |
erect to ascending, branched. |
Leaves | palmate; stipules ovate to oblong, 0.6–1 cm, margins entire, apex acuminate to cuspidate; petiole 0.5–6 cm; petiolules to 0.5 mm; leaflets 3, blades obovate, oblanceolate, or elliptic, 0.6–1.6 × 0.3–1.2 cm, base cuneate, veins obscure or slightly thickened, margins subentire to serrate, apex rounded, retuse, surfaces pubescent. |
palmate; stipules obliquely ovate, 0.4–1.2 cm, margins entire or slightly serrate, apex acuminate; petiole 1–5 cm; petiolules 0.5 mm; leaflets 3, blades oblanceolate, obovate, or obcordate, 0.4–1.7 × 0.3–1.1 cm, base cuneate, veins fine or slightly thickened, margins setose, often dentate distally, apex usually retuse, rarely rounded, surfaces villous. |
Inflorescences | terminal or subterminal, usually paired, sometimes one head slightly stalked, partially hidden by terminal leaves and stipules, 10–40-flowered, ovoid or subglobose, 0.8–2.5 × 0.5–2 cm; involucres absent, involucrelike structure formed from terminal leaves and stipules. |
axillary or terminal, 10–40-flowered, globose, 0.5–1.3 × 0.4–1.2 cm; involucres flattened or bowl-shaped, 0.4–1 cm, when folded, nearly completely hiding calyces, villous, incised 1/2 their length, lobes 5–12, lanceolate-ovate, entire or slightly toothed proximally, acuminate. |
Peduncles | 0–0.2 cm. |
1–8 cm. |
Pedicels | absent; bracteoles broadly ovate to linear, 1–2 mm. |
absent; bracteoles absent. |
Flowers | 5.5–7.5 mm; calyx tubular, 4–5 mm, pubescent, veins 5–10, tube 1.5–2 mm, lobes subequal, subulate, orifice open; corolla usually purple or pink, rarely white, 5–7 mm, banner obovate-oblong, 6–7 × 2–3 mm, apex rounded, slightly denticulate. |
4–6 mm; calyx campanulate-tubular, 3–5.5 mm, pubescent, veins 10, tube 1.8–2.5 mm, lobes ± equal, triangular-aristate, margins hyaline, wavy, orifice open; corolla white or pink to lavender, 4–6 mm, banner oblong, 3–6 × 1–2 mm, apex emarginate. |
Legumes | oblong, 2.5–3 mm. |
broadly ellipsoid, 1.5–2 mm. |
Seeds | 1, yellow, mottled, ellipsoid, 1.6–2 mm, smooth. |
1, yellow, reddish mottled, oblong, 1.5 mm, smooth. |
2n | = 16. |
= 16. |
Trifolium macraei |
Trifolium microcephalum |
|
Phenology | Flowering May–Jun. | Flowering Mar–Jul. |
Habitat | Grassy fields, sandy ocean bluffs. | Meadows, roadsides, stream banks, forest clearings, grassy slopes. |
Elevation | 0–800 m. (0–2600 ft.) | 0–2500 m. (0–8200 ft.) |
Distribution |
CA; OR; South America (Chile)
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AK; AZ; CA; ID; MT; NV; OR; WA; BC; Mexico (Baja California)
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Discussion | Trifolium macraei was described from specimens collected in Chile; the South American plants have broader banners, smaller auricles on the wing petals, and styles that are barely curved upwards distally (D. Isely 1998). Further examination of the disjunct populations may reveal other differences and prompt reconsideration of the identity of North American specimens. The record from Massachusetts is a waif. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Trifolium microcephalum is common in much of its range in California and northward into Oregon, and is rare in much of the rest of its range. It is closely allied with the Chilean T. vernum Philippi (N. W. Ellison et al. 2006), which it resembles greatly, and from which it is distinguished by its shorter calyx lobes (M. Zohary and D. Heller 1984). (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 | T. bicephalum, T. catalinae, T. mercedense, T. traskiae | Lojaconoa microcephala, T. microcephalum var. bipedale, T. microcephalum var. lemmonii |
Name authority | Hooker & Arnott: Bot. Misc. 3: 179. (1833) | Pursh: Fl. Amer. Sept. 2: 478. (1813) |
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