Dudleya subg. Stylophyllum

(Britton & Rose) Moran

Desert Pl. Life. 14: 156. 1942..

Basionym: Stylophyllum Britton & Rose New N. Amer. Crassul. 33. 1903
Treatment appears in FNA Volume 8. Treatment on page 173. Mentioned on page 172, 177, 179, 192.

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

None.

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
perigynous +  and hypogynous +
Reid V. Moran +
(Britton & Rose) Moran +
Stylophyllum +
lobed +  and toothed +
distal +, terete +  and laminar +
bifurcate +
elongate +
whorled +, opposite +  and alternate +
sw Calif. +  and nw Mexico +
branched +  and simple +
ascending;spreading +
erect;spreading +
axillary +  and terminal +
sessile +, petiolate +  and subclasping +
alternate +  and crowded +
persistent +
wider than tall +
semi-inferior +  and superior +
tenuinucellate +, crassinucellate +  and bitegmic +
0 cm0 mm <br />0 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
perigynous +  and hypogynous +
red +, orange +, yellow +  and white +
to middle +  and connate +
spreading +  and ascending +
outcurved +
(3-)4-5(-12)[-30+]-carpellate +
ascending +  and spreading +
Desert Pl. Life. +
cross-ribbed +  and ribbed +
1 +  and many +
adnate +  and free +
antipetalous +
2-branched +  and simple +
distinct +
Dudleya subg. Stylophyllum +
subgenus +
cylindric +  and 5-gonal +
perennial +, biennial +  and annual +