Dudleya subg. Stylophyllum
Desert Pl. Life. 14: 156. 1942..
Stems above ground, caudices, branching, elongate. Leaves persistent; petiole absent; blade laminar or terete distal to clasping base, turgid ± throughout. Cymes: branches 2-several, simple or bifurcate; cincinni not or scarcely circinate. Pedicels erect, mostly less than 3 mm. Flowers: petals ascending, outcurved, or spreading from near middle, corolla widely open; pistils (well separated), usually not connivent (connivent in D. virens), ascending to spreading in flower and fruit, somewhat gibbous adaxially in fruit.
Distribution
sw Calif., nw Mexico.
Discussion
Species 9 (6 in the flora).
Primitive members of subg. Stylophyllum, such as Dudleya virens, have open corollas, with petals spreading from near the middle, in contrast to the prismatic or tubular corollas of subg. Dudleya. Also included in this subgenus, for want of a better place, are the tetraploid D. traskiae and two Mexican polyploids, all with campanulate, and thus intermediate, corollas. These are taken to be allopolyploids between members of subg. Dudleya and primitive members of subg. Stylophyllum. More-advanced members are those with cylindric leaves, ending with D. attenuata, which also has the most reduced inflorescence.
Selected References
Lower Taxa
Key
| 1 | Rosette leaf blades flat or convex (sometimes semiterete), at least in central part of blade, 2-6 times wider than thick | > 2 |
| 1 | Rosette leaf blades terete or subterete except at widened, clasping base, less than 2 times wider than thick | > 4 |
| 2 | Leaves with resinous odor, blade viscid, appearing oily, light to dark or yellowish green, not farinose; mainland. | Dudleya viscida |
| 2 | Leaves without resinous odor, blade not viscid or oily, whitish or light green, sometimes farinose; mostly insular | > 3 |
| 3 | Petals white or rosy, widespreading or slightly reflexed from middle; leaf blades 2-5 times wider than thick. | Dudleya virens |
| 3 | Petals bright yellow, ascending near base and outcurved; leaf blades 4-6 times wider than thick. | Dudleya traskiae |
| 4 | Cyme branches 1-3, simple; caudices 0.3-1 cm wide; leaf blades somewhat clavate, 2-5 mm thick; follicles ascending. | Dudleya attenuata |
| 4 | Cyme branches 2-15, usually 1-2 times bifurcate; caudices 1-3.5 cm wide; leaf blades terete or subterete, 4-9 mm thick; follicles ascending to widely spreading | > 5 |
| 5 | Rosette leaf blades farinose, 6-15(-23) cm; cymes 3-5-branched, rounded, 1.5-3 × 0.4-1 dm; pedicels 2-5 mm; styles 2-3.5 mm. | Dudleya densiflora |
| 5 | Rosette leaf blades not farinose, 8-20(-40) cm; cymes 2-15-branched, flat-topped to mostly cylindric, 0.4-1 × 0.4-1 dm; pedicels 1-2(-5) mm; styles 1.5-2 mm. | Dudleya edulis |