Trifolium mucronatum subsp. lacerum

(Greene) J. M. Gillett

Canad. J. Bot. 58: 1444. 1980.

Common names: Spinytooth clover
Basionym: Trifolium lacerum Greene Erythea 2: 182. 1894
Synonyms: T. arizonicum Greene T. fistulosum A. E. Vaughan T. involucratum var. arizonicum (Greene) McDermott T. ortegae Greene T. oxyodon Greene ex Rydberg T. variegatum var. parunuweapensis S. L. Welsh T. wormskioldii var. arizonicum (Greene) Barneby T. wormskioldii var. ortegae (Greene) Barneby
Treatment appears in FNA Volume 11.

Herbs perennial, 10–65 cm, glabrous; rhizomes absent or relatively short, roots taproots, slender. Stems erect or decumbent, sparsely branched. Leaves palmate; stipules lanceolate to narrowly ovate, 1.5–2 cm, margins toothed or lacerate, apex acuminate; petiole 1–3.5 cm; petiolules to 0.5 mm; leaflet blades linear, elliptic, or obovate, 0.8–2.5 × 0.1–0.3 cm, base cuneate, veins thickened, margins entire or finely serrate to setose-spinulose, apex acute or apiculate, surfaces glabrous. Peduncles 4–6 cm. Inflorescences terminal or axillary, 8–20-flowered, subglobose to globose, 1.5–2 × 1.5–4 cm; involucres broadly campanulate, 10–22 mm, incised to 3/4 their length, lobes 10+, triaristate to lacerate. Pedicels straight, 0.5 mm; bracteoles subulate or broadly wavy-margined, 2–3 mm. Flowers 12–20 mm; calyx tubular-conic, 5–7 mm, glabrous, veins 10, tube 2–2.5 mm, lobes ± equal, 6–8 mm, abaxial lobe longer than tube, orifice open; corolla white, lavender, or purple, sometimes with different colors within inflorescence, 11–13 mm, banner narrowly oblong [broadly obovate-oblong], 11–13 × 4 mm, apex rounded. Legumes oblong, 3–6 mm. Seeds 2–4, olive, reniform, 1.3–1.5 mm, smooth. 2n = 16.


Phenology: Flowering Jun–Sep.
Habitat: Damp meadows, seeps, along streams in pine forests.
Elevation: 700–2500 m.

Distribution

Ariz., Calif., Colo., N.Mex., Tex., Mexico (Chihuahua, Coahuila, Sonora).

Discussion

The single California record for subsp. lacerum was collected in 1925 in Inyo County.

Selected References

None.

Lower Taxa

None.
Michael A. Vincent +  and John M. Gillett† +
(Greene) J. M. Gillett +
Trifolium lacerum +
Spinytooth clover +
Ariz. +, Calif. +, Colo. +, N.Mex. +, Tex. +, Mexico (Chihuahua +, Coahuila +  and Sonora). +
700–2500 m. +
Damp meadows, seeps, along streams in pine forests. +
Flowering Jun–Sep. +
Canad. J. Bot. +
T. arizonicum +, T. fistulosum +, T. involucratum var. arizonicum +, T. ortegae +, T. oxyodon +, T. variegatum var. parunuweapensis +, T. wormskioldii var. arizonicum +  and T. wormskioldii var. ortegae +
Trifolium mucronatum subsp. lacerum +
Trifolium mucronatum +
subspecies +