Dudleya attenuata subsp. attenuata

Common names: Orcutt’s dudleya
Synonyms: Dudleya attenuata subsp. orcuttii Stylophyllum orcuttii Britton Stylophyllum parishii
Treatment appears in FNA Volume 8. Treatment on page 176. Mentioned on page 193.

Caudices 0.5–2 dm × 0.3–1[–1.5] cm, clumps 1–4 dm diam. Leaves without resinous odor; rosette (lax), 5–20-leaved, 2–5(–10) cm diam.; blade often purplish, linear to linear-oblanceolate and somewhat clavate, terete or flattened adaxially towards base, 2–10 × 0.2–0.5 cm, 2–5 mm thick, to 2 times wider than thick, base 5–15 mm wide, surfaces farinose, not viscid, not oily. Inflorescences: cyme 1–3-branched, obpyramidal, (2–15(–20) × 1–10 dm); branches simple; cincinni 3–15-flowered, not circinate, 2–11 cm; floral shoots 0.5–2.5 dm × 1–3 mm; leaves 5–10, ascending, linear-lanceolate, (turgid), 5–3.5 × 0.2–0.5 cm. Pedicels 0.5–3 mm. Flowers: petals widespreading or somewhat ascending from near middle, connate 0.5–1 mm, white often flushed with rose, especially on keel, triangular-ovate, 6–10 × 1.5–3 mm, apex acute, corolla ca. 10 mm diam.; pistils erect, 4–7 mm; styles 1–2.5 mm. Follicles ascending, with adaxial margins ca. 45–60º above horizontal. 2n = 34 [68, Mexico].

Phenology: Flowering spring.
Habitat: Bluffs, flats, and rocky slopes near sea
Elevation: 0-10 m


V8 352-distribution-map.gif

Calif., Mexico (Baja California).


Of conservation concern.

Subspecies attenuata is abundant southward in Mexico but barely enters southwestern San Diego County on the coast, where it is now rare. It is considered seriously threatened in California. Dudleya attenuata subsp. orcuttii (Rose) Moran was thought to be distinct in having white or rose-tinged petals; subsequent field work showed that some populations include plants with yellow petals (R. V. Moran 2001). Stylophyllum parishii was supposedly from Pala, 90 kilometers to the north of the southwestern San Diego County population of subsp. attenuata, and was based on cultivated plants that apparently were mislabeled (Moran 1943).

In northwest Baja California subsp. attenuata hybridizes with Dudleya brittonii, D. edulis, D. formosa, and D. variegata; all the hybrids apparently are rare.

Selected References


Lower Taxa

Reid V. Moran +
(S. Watson) Moran +
Cotyledon attenuata +
Orcutt’s dudleya +
Calif. +  and Mexico (Baja California). +
0-10 m +
Bluffs, flats, and rocky slopes near sea +
Flowering spring. +
Desert Pl. Life +
Dudleya attenuata subsp. orcuttii +, Stylophyllum orcuttii +  and Stylophyllum parishii +
Dudleya attenuata subsp. attenuata +
Dudleya attenuata +
subspecies +