Trifolium productum

Herbs perennial, 15–45 cm, glabrous. Stems ± erect, loosely cespitose, branched. Leaves basal and cauline, palmate; stipules ovate-lanceolate, 0.5–2 cm, margins usually entire, sometimes lobed, apex acute to acuminate; petiole 0.5–12 cm; petiolules 1 mm; leaflets 3, blades lanceolate or elliptic, 0.5–2 × 0.3–1.3 cm, base cuneate, veins prominent, margins serrate, apex acute, apiculate, surfaces glabrous. Peduncles 2–13 cm, slightly twisted apically. Inflorescences terminal or axillary, 15–30-flowered, ellipsoid or conic, 1.5–2 × 1–3 cm, rachis prolonged beyond flowers, undivided or forked, often bearing sterile flower buds distally; involucres absent. Pedicels strongly reflexed in fruit, 0.5 mm; bracteoles minute, lanceolate. Flowers 12–14 mm; calyx pink to purple, campanulate, 3–3.5 mm, glabrous, veins 10 (5 sometimes faint), tube 1.5–1.7 mm, lobes subequal, triangular-subulate, orifice open; corolla pink to deep purple, 12–14 mm, banner oblong, 12–14 × 4–5 mm, apex rounded or retuse. Legumes obliquely ellipsoid, 5 mm. Seeds 1 or 2, brown, often purple-mottled, flattened ovoid, 2–3 mm, smooth. 2n = 16.

Phenology: Flowering May–Sep.
Habitat: Open coniferous woods, rocky places, stream banks, grassy meadows, near springs.
Elevation: 1100–2800 m.

Calif., Nev., Oreg.

Discussion

Trifolium productum is morphologically most similar to T. kingii, from which it differs by its glabrous calyces and inflorescence rachises surpassing the flowers to 1.5 cm and apically forked (M. Zohary and D. Heller 1984). Trifolium productum is geographically isolated from T. kingii; the former is restricted to northern California, western Oregon, and western Nevada, while the latter is restricted to Utah and easternmost Nevada (J. M. Gillett 1972).

Selected References

None.

Lower Taxa