Trifolium sonorense |
Trifolium nanum |
|
---|---|---|
Sonoran clover |
dwarf clover |
|
Habit | Herbs perennial, 25–38+ cm, pubescent. | Herbs perennial, 4–10 cm, glabrous. |
Stems | prostrate, branched. |
cespitose, matted, acaulescent. |
Leaves | 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. |
palmate; stipules ovate-lanceolate, 1–2 cm, margins entire, apex acuminate, sometimes forked; petiole 0.3–2.5 cm; petiolules to 0.2 mm; leaflets 3, blades oblanceolate or obovate, 0.3–1.2 × 0.1–0.5 cm, base cuneate, veins ± thickened, margins toothed, apex acute or acuminate, surfaces glabrous. |
Inflorescences | 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. |
terminal or axillary, 1–4-flowered, umbellate, 1.5–2 × 0.5–1 cm, rachis not prolonged beyond flowers; involucres a narrow, membranous, dentate rim, 1 mm. |
Peduncles | 2.8–5 cm. |
0.5–3 cm. |
Pedicels | reflexed in fruit, 1–3 mm; bracteoles linear-triangular, 0.5 mm. |
erect, 1 mm; bracteoles cuplike, membranous, 0.5–1 mm. |
Flowers | 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. |
15–20 mm; calyx campanulate, 4–7 mm, glabrous, veins 5–10, tube 3–4 mm, lobes equal, triangular-acuminate, orifice open; corolla purple or violet, 15–20 mm, banner oblong, 15–20 × 7–9 mm, apex rounded, slightly retuse. |
Legumes | obovoid, 4.3–4.4 mm. |
oblanceoloid, 9–11 mm. |
Seeds | 2, brownish orange or olive-brown, globose or broadly reniform, 1.2–1.7 mm, smooth. |
4–6, tan or brown, mitten-shaped, 2–2.2 mm, smooth, dull. |
2n | = 16. |
= 16. |
Trifolium sonorense |
Trifolium nanum |
|
Phenology | Flowering Aug–Oct. | Flowering Jun–Aug. |
Habitat | Dry stream banks, grassy places. | Alpine slopes, tundra. |
Elevation | 1500–1800 m. (4900–5900 ft.) | 2600–4500 m. (8500–14800 ft.) |
Distribution |
AZ; Mexico (Chihuahua, Jalisco, Sinaloa, Sonora) |
CO; MT; NM; UT; WY
|
Discussion | 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.) |
Trifolium nanum is abundant in alpine tundra areas from Montana through Wyoming and Utah into Colorado (where it is most common) and northern New Mexico; populations are morphologically variable with regard to leaf size and petiole length, and this variability appears to be related to water availability (J. M. Gillett 1965). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Name authority | T. K. Ahlquist & Vincent: Phytoneuron 2018-1: 1, fig. 1. (2018) | Torrey: Ann. Lyceum Nat. Hist. New York 1: 35, plate 3, fig. 4. (1824) |
Web links |