A REVISION OF DUDLEYA, Subgenus Stylophyllum - II


1. Dudleya traskae (Rose) Moran. Desert Plant Life. 14: 153. 1942.

Stylophyllum Traskae Rose, Bull. N. Y. Bot. Gard. 3: 34. 1903. Cotyledon Traskae Fedde, Just's Bot. Jahresber. 31(1): 829. 1904. Echeveria Traskae Berger in E. & P., Nat. Pflanzenfam. 18a: 480. 1930.


Caudex short and erect, mostly 1-2 cm thick, branching to form clumps sometimes with 20-100 or more heads; rosette leaves about 25-55, close-set, spreading in the single rosette or erect in clustered rosettes, strap-oblanceolate or strap-shaped, sharply acute or somewhat acuminate, usually concave above, with sub-acute margins except towards the apex, 4-15 cm long, 1-4 cm broad, 4-6 x broader than thick, glaucous at least when young; the base 1-4 cm broad, 2-4 mm high; flowertng stems 2-3 dm high; cauline leaves deltoid-ovate, acute, horizontal or slightly ascending, the lowest about 3 cm long; inflorescence flat-topped, with about 3 major branches which bifurcate once or twice; pedicels stout, mostly 1-3 mm long; sepals deltoid to deltoid-ovate, acute, 2.5-4 mm long: petals nearly erect in the lower half, curving outward above, connate 1-1.5 mm, narrowly ovate, acute, 8-10.5 mm long, 3-4 mm broad, bright yellow, becoming somewhat red-veined; stamens 6.5-8.5 mm long, adnate to the petals for 1.5-2.5 mm; anthers 1.5-1.7 mm long; carpels .connate about 1 mm, in age somewhat spreading, 6.5-8 mm long; styles about 2.5 mm long; seeds not seen.


TYPE: Fragments from and photograph of a specimen collected on Santa Barbara Island, California, May, 1901, by Blanche Trask; in the United States National Herbarium. Meager fragments from the type at the New York Botanical Garden. I have been unable to find the original of the photograph; presumably it was destroyed with the bulk of Mrs. Trask's collections in the San Francisco fire of 1906.


DISTRIBUTION: Known only from tiny Santa Barbara Island. I saw only two colonies, one on the south slope and one on the west, both, at about 100 m elevation.


SPECIMENS EXAMINED: Santa Barbara Island, B. Trask in 1901 (NY, US), R. M. 822 (Mor), 823 (CAS, CU, DS, RSA, UC, US).


ILLUSTRATIONS: Fig. 1; Desert Plant Life. 14: 153, 157.


Jepson (1936) included Stylophyllum traskae with the other Californian insular Stylophyllums in his Echeveria vtscida var. insularis. Munz (1935) included it with Stylophyllum albidum and S. insulare in Echeveria albida. Since Dudleya traskae is very distinct from any other known species, its reduction to synonymy is understandable only in view of the extreme paucity of material in the herbaria before last year.


Dudleya traskae differs from all other members of the subgcnus in its bright yellow petals, whose nearly erect position is approached only in D. anomala. The leaves are broader and thinner than those of any other species. The inflorescence is of a form which occurs only rarely in the other species. As was pointed out before, D. traskae is close to the subgenus Eududleya.



Fig. 1. DUDLEYA TRASKAE (Rose) comb, noy. (Stylophyllum Traskae Rose, Bull. N. Y. Bot. Gard. 3: 34. 1903.) Plant in the wild, Santa Barbara Island, California (type locality), 100 m, April 26, 1941. R. M. 822 Kodachrome.


© Desert Plant Life, 1942