Dudleya subg. Dudleya in Flora of North America @ efloras.org

10b. Dudleya Britton & Rose subg. Dudleya

Stems above ground, caudices, branching or sometimes simple, short or elongate. Leaves usually persistent (withering in early summer in D. cymosa subsp. marcescens and D. parva); petiole absent; blade mostly laminar, sometimes subterete, turgid ± throughout. Cymes: branches 2-3(-6), simple or bifurcate; cincinni circinate or not. Pedicels erect to pendent, 1-35 mm. Flowers: petals erect to, rarely, ascending (sometimes tips outcurved), corolla barely open, tubular or tightly 5-gonal (loosely tubular, not tightly 5-gonal in D. farinosa), free margin of each petal usually connivent to adjacent petals (usually not connivent in D. farinosa); pistils usually connivent and erect in flower (suberect and not connivent in D. stolonifera), nearly erect or slightly ascending, not gibbous in fruit.

Species ca. 40 (15 in the flora): sw United States, nw Mexico.

G. A. Levin and T. W. Mulroy (1985) studied floral morphology, nectar production, and breeding systems in 21 taxa of subg. Dudleya from throughout the north-south range. A few are pollinated primarily by hummingbirds, although also having high self-fertility, and several primarily by bees and long-tongued flies; all those studied were self-compatible. Levin and Mulroy concluded that the breeding system of Dudleya favors outcrossing but allows self-fertilization. Subgenus Dudleya is notable in that the epipetalous filaments are usually shorter than antisepalous ones and adnate higher.

SELECTED REFERENCES Levin, G. A. and T. W. Mulroy. 1985. Floral morphology, nectar production, and breeding systems in Dudleya subgenus Dudleya (Crassulaceae). Trans. San Diego Soc. Nat. Hist. 21: 57-70. Nakai, K. M. 1987. Some new and reconsidered California Dudleya (Crassulaceae). Madroño 34: 334-353.

1 Petals connate 4.5-10 mm (1/2 their lengths); cyme branches often twisted at base (flowers on underside); pedicels pendent, declined, spreading, or ascending to erect in flower, usually bent sharply upward from near middle in fruit; rosettes solitary, 5-60 cm diam., blade often chalky white (2)

+ Petals connate 1-3(-4.5) mm (to 1/3 their lengths); cyme branches not twisted (flowers on topside); pedicels ascending to erect in flower, not bent in fruit; rosettes 1-300, 0.8-35 cm diam., blade pale to bright green or blue-green, gray-blue, or gray-green, sometimes becoming purplish or reddish (3)

2 (1) Caudices 1-4 cm diam.; rosettes 10-35-leaved, blade apices acute or usually long-acuminate; pedicels erect or ascending; petals red to apricot yellow; desert mountains. 20 Dudleya arizonica

+ Caudices 4-10 cm diam.; rosettes 30-80-leaved, blade apices acuminate to cuspidate; pedicels declined or pendent; petals red; coastal side of mountains. 21 Dudleya pulverulenta

3 (1) Caudices with axillary branches; unripe follicles ascending; calyces 3-4 × 5.5-7 mm. 7 Dudleya stolonifera

+ Caudices simple or branching apically, axillary branches absent; unripe follicles erect; calyces 3-9 × 3-9 mm (4)

4 (3) Rosettes 10-30 cm diam., 20-45-leaved; caudices simple, 2-8 cm diam.; leaf blades usually not farinose, 3-7 cm wide; insular. 13 Dudleya candelabrum

+ Rosettes usually 1-15(-35) cm diam., 5-25(-65)-leaved; caudices simple or branched, 0.5-3.5 cm diam.; leaf blades sometimes farinose, usually to 3 cm wide, rarely to 6 cm; mainland and insular (5)

5 (4) Leaves withering in early summer; cymes mostly 2-4-branched (6)

+ Leaves persistent; cymes usually 1-6-branched (7)

6 (5) Petals pale or bright yellow, mustard yellow, or red, apex mostly narrowly acute; pedicels 5-15 mm; leaf blades 0.5-1.2 cm wide 8 Dudleya cymosa (in part)

+ Petals pale yellow, sometimes red-lineolate, apex broadly acute; pedicels 1-3 mm; leaf blades 0.3-0.7 cm wide 10 Dudleya parva

7 (5) Caudices usually 10-60 cm; rosette leaf blades usually 3-8 mm thick (8)

+ Caudices usually 0.1-10 cm; rosette leaf blades 1-6 mm thick (11)

8 (7) Corollas loosely tubular, free margins of each petal usually not connivent to adjacent petals, petals pale yellow; rosette leaf blades ovate-oblong. 14 Dudleya farinosa

+ Corollas tightly 5-gonal, free margins of each petal usually connivent to adjacent petals, petals whitish, pale yellow, or bright yellow to orange or red; rosette leaf blades oblong or oblong-lanceolate to oblong-obovate (9)

9 (8) Petals pale yellow or whitish, 8-12 mm, tips sometimes out- curved; insular. 15 Dudleya greenei

+ Petals bright yellow to orange or red, 8-16 mm, tips erect; insular or mainland (10)

10 (9) Rosette leaf blades 0.5-4 cm wide; petals mostly bright yellow to red. 18 Dudleya cespitosa

+ Rosette leaf blades 1.5-5 cm wide; petals red or bright yellow marked with red and appearing orange 19 Dudleya palmeri

11 (7) Pedicels usually 5-20 mm (12)

+ Pedicels usually 1-6(-17) mm (13)

12 (11) Rosette leaf blades usually oblanceolate to spatulate, rhombic-oblanceolate, oblong, elliptic, ovate, or sometimes triangular-oblong, 1.5-12(-17) × 0.5-6 cm, apex acute to acuminate or cuspidate or subobtuse; petal apices narrowly acute; cyme branches simple or 1-3 times bifurcate; cincinni 1-5(-17) cm. 8 Dudleya cymosa (in part)

+ Rosette leaf blades oblong-lanceolate, 3-15 × 0.5-2.5 cm, apex narrowly acute; petal apices acute; cyme branches simple or bifurcate; cincinni 1-18 cm. 12 Dudleya saxosa

13 (11) Petals pale yellow or straw yellow to medium yellow or almost white (rarely bright yellow) and often red-lineolate, 1.5-4.5 mm wide; rosette leaf blades 0.6-6(-11) × 0.2-2 cm; floral shoots 2-25 cm (14)

+ Petals bright yellow to usually red, 2.5-5 mm wide; rosette leaf blades 2-30 × 0.4-4 cm; floral shoots (3-)15-120 cm (15)

14 (13) Rosette leaves linear or elliptic to oblong-lanceolate or tapering from base; cincinni 3-15 cm. 9 Dudleya abramsii

+ Rosette leaves triangular-ovate; cincinni 1-3 cm. 16 Dudleya gnoma

15 (13) Caudices 1-3 cm diam.; leaf blade bases 1-3 cm wide. 11 Dudleya lanceolata

+ Caudices 0.2-1 cm diam.; leaf blade bases 0.5-0.8 cm wide. 17 Dudleya verityi