San Gabriel Mountains dudleya

Stylophyllum densiflorum Rose in N. L. Britton and J. N. Rose, New N. Amer. Crassul., 36. 1903, based on Cotyledon nudicaulis Abrams, Bull. S. Calif. Acad. Sci 2: 42. 1903 (as nudicaule), not Lamarck 1786; Echeveria nudicaulis Munz; Stylophyllum nudicaule (Munz) Abrams

Caudices to 2 dm × 1-2.5 cm, clumps to 3 dm diam. Leaves without resinous odor; rosette 20-40-leaved, 7-25 cm diam.; blade green, appearing whitish, linear, terete or subterete, base flattened, 6-15(-23) × 0.6-1.2 cm, 5-8 mm thick, 1-1.5 times wider than thick, base 10-20 mm wide, surfaces farinose, not viscid, not oily. Inflorescences: cyme 3-5-branched, rounded, (1.5-3 × 0.4-1 dm); branches usually 1-2 times bifurcate; cincinni 2-8-flowered, scarcely circinate, 2-4 cm; floral shoots 1-3 dm × 2-4 mm; leaves 5-15, erect, lanceolate, 1-4 × 0.5-1.2 cm. Pedicels 2-5 mm. Flowers: petals spreading from middle, connate 0.5-2 mm, white or pinkish, narrowly ovate, 5-10 × 2-3 mm, apex acute, corolla 12-20 mm diam.; pistils erect, 6-9 mm; styles 2-3.5 mm. Follicles widely spreading, with adaxial margins 10-45º above horizontal. 2n = 34.

Flowering spring. Cliffs and steep rocky slopes; of conservation concern; 100-600 m; Calif.

Dudleya densiflora is a distinct endemic that is very local and now rare at the south base of the San Gabriel Mountains near the mouth of San Gabriel Canyon; it is considered seriously threatened (California Native Plant Society, http://cnps.web.aplus.net/cgi-bin/inv/inventory.cgi).

Dudleya densiflora is in the Center for Plant Conservation’s National Collection of Endangered Plants.