Trifolium bifidum |
Trifolium sonorense |
|
---|---|---|
notch-leaf clover, Pinole clover, piñole clover |
Sonoran clover |
|
Habit | Herbs annual, 5–55 cm, sparsely pubescent or glabrous. | Herbs perennial, 25–38+ cm, pubescent. |
Stems | erect, branched. |
prostrate, branched. |
Leaves | palmate; stipules ovate to lanceolate, 0.8–1.5 cm, margins entire or slightly serrate, apex acicular; petiole 1–7 cm; petiolules to 0.5 mm; leaflets 3, blades narrowly obcordate, obovate, oblanceolate, or linear, 1–2.5 × 0.3–0.7 cm, base cuneate, veins moderately thickened, margins serrate distally or entire, apex rounded, truncate, shallowly to deeply retuse, or deeply 2-fid, surfaces glabrous or hairy abaxially along midvein. |
palmate; stipules narrowly triangular, 0.7–1.7 cm, margins entire or finely serrulate, apex usually acute or acuminate, sometimes 2-fid; petiole 0.3–5 cm; petiolules to 1 mm; leaflets 3, blades obovate to obcordate, 0.9–1.6 × 0.7–1.2 cm, base cuneate, veins moderately thickened, margins serrate to weakly so, apex rounded or emarginate, mucronulate, surfaces slightly hairy abaxially, glabrous adaxially. |
Inflorescences | axillary or terminal, 5–30-flowered, globose to subglobose, 0.8–1.5 × 0.8–1.5 cm, rachis prolonged beyond flowers; involucres a very narrow rim, to 0.5 mm. |
axillary, 10–20-flowered, depressed-globose or globose, 0.8–1.6 × 0.9–1.6 cm, rachis prolonged beyond flowers; involucres a narrow rim, or slightly proximally connate bracteoles of proximal flowers, 0.1–0.5 mm. |
Peduncles | 3–8 cm. |
2.8–5 cm. |
Pedicels | reflexed in fruit, 1–3 mm; bracteoles broadly triangular, membranous, to 0.5 mm. |
reflexed in fruit, 1–3 mm; bracteoles linear-triangular, 0.5 mm. |
Flowers | 6–8 mm; calyx campanulate, 3–3.6 mm, slightly hairy or glabrous, veins 10, tube 1–1.5 mm, lobes unequal, subulate, margins green or purple, orifice open; corolla pink or purple, 5–7 mm, banner elliptic to oblong, 5–7 × 3–4 mm, apex rounded, apiculate. |
5.7–6.7 mm; calyx tubular, 3.3–6.5 mm, pubescent, veins 10, tube 0.8–1 mm, lobes subequal, narrowly triangular, orifice open; corolla white or pink, 5.3–6.5 mm, banner obovate, 5.3–6.5 × 2.8–3.8 mm, apex broadly rounded or broadly acute. |
Legumes | stipitate, obovoid, 3–4 mm. |
obovoid, 4.3–4.4 mm. |
Seeds | 1 or 2, brown, mottled, oblong, 2–3 mm, smooth. |
2, brownish orange or olive-brown, globose or broadly reniform, 1.2–1.7 mm, smooth. |
2n | = 16. |
= 16. |
Trifolium bifidum |
Trifolium sonorense |
|
Phenology | Flowering Apr–Jun. | Flowering Aug–Oct. |
Habitat | Open woodlands, fields, roadsides, slopes, stream margins, meadows. | Dry stream banks, grassy places. |
Elevation | 0–1200 m. (0–3900 ft.) | 1500–1800 m. (4900–5900 ft.) |
Distribution |
CA; OR; WA; BC; Mexico (Baja California)
|
AZ; Mexico (Chihuahua, Jalisco, Sinaloa, Sonora) |
Discussion | Trifolium bifidum ranges from Baja California, Mexico, northward through California to scattered sites in Oregon, Washington, and British Columbia. Recent re-evaluation of Trifolium bifidum and related species showed complete overlap in characters for the two varieties that have been recognized previously, with no clear distinctions between them (L. Rogers, pers. comm.). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Trifolium sonorense has long been equated with T. amabile Kunth, from which T. K. Ahlquist (2012) and also Ahlquist & M. A. Vincent have shown it to be distinct by longer sepal lobes (more than 3 mm), keel petal claws (more than 1.7 mm), and filament tubes (more than 3.6 mm). Trifolium sonorense is known from western Mexico and southernmost Arizona (Cochise County), largely in the Sonoran Desert region, and in mountainous Jalisco. (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. bifidum var. decipiens, T. greenei, T. hallii | |
Name authority | A. Gray: Proc. Calif. Acad. Sci. 3: 102. (1864) | T. K. Ahlquist & Vincent: Phytoneuron 2018-1: 1, fig. 1. (2018) |
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