Trifolium ciliolatum

Herbs annual, 5–50 cm, glabrous or sparsely hairy. Stems erect, branched. Leaves palmate; stipules ovate-lanceolate, 1–1.5 cm, margins entire, sometimes ciliate, apex acuminate; petiole 1–13 cm; petiolules 0.5 mm; leaflets 3, blades elliptic to oblong or obovate, 0.8–3.5 × 0.5–1.5 cm, base cuneate, veins thickened, margins serrate proximally, obscurely denticulate distally, apex usually rounded or retuse, rarely acute, surfaces glabrous. Peduncles 2.5–12 cm. Inflorescences axillary or terminal, 10–30-flowered, ovoid to subglobose, 0.7–2.2 × 0.5–2 cm; involucres a narrow rim, 0.5 mm, membranous, dentate. Pedicels erect becoming reflexed, 0.5–6 mm; bracteoles linear or cup-shaped, to 1 mm. Flowers 6–13 mm; calyx broadly campanulate, 5–11 mm, glabrous, veins 10, tube 1–5 mm, lobes unequal, elliptic to linear, margins hyaline, dentate or pectinate, ciliate, sinuses narrow, orifice open; corolla white, pink, or purple, 5–13 mm, banner broadly ovate, 6–13 × 4–7 mm, apex rounded, apiculate. Legumes short-stipitate, ovoid, 5–10 mm. Seeds 1 or 2, brown, mottled, ovoid, 2.5–3 mm, smooth. 2n = 16.

Phenology: Flowering Apr–Jun.
Habitat: Oak-pine chaparral, meadows, roadsides.
Elevation: 0–1500 m.

Calif., Oreg., Wash., Mexico (Baja California).

Discussion

Trifolium ciliolatum is relatively widespread in California and is found in scattered sites in Baja California, Oregon, and Washington.

Trifolium ciliatum Nuttall (1848), which pertains here, is a later homonym of T. ciliatum E. D. Clarke (1813).

Selected References

None.

Lower Taxa