Euphorbia fendleri Torrey & A. Gray, fendler spurge. Perennial herb, many–stemmed at base, < 10 cm tall; shoots with only cauline leaves, glabrous and glaucous.
Stems cylindric, 1 mm diameter, internodes to 2.5 mm long and swollen above node, pale green or pink–tinged, glaucous.
Leaves opposite decussate, simple, petiolate, with stipules; stipules 2, not fused to adjacent stipule at node, ± acuminate, 0.6—1 mm long, pale green and glaucous, tip sometimes purple–red; petiole hemi–cylindric, 1—2 mm long, yellow–green; blade ovate to inversely heart–shaped, 5—7 × 2.5—5 mm, cordate to truncate or broadly tapered and somewhat oblique at base, entire, obtuse to acute at tip, inconspicuously pinnately veined with midrib scarcely raised on lower surface.
Inflorescence cyathium (= involucre with staminate flowers and 1 pistillate flower), appearing terminal, solitary and paired with elongating vegetative shoot; peduncle 1 mm long; cyathium ca. 2 mm wide (including spreading glands, lacking appendages); involucre ± bell–shaped, initially 1 × 1 mm, green and glaucous, with 5 bracts and 4 glands, the bracts of involucre fused most of length, the glands alternate with bracts (1 absent), nectar–producing, raised, horizontally oval, 0.5—0.6 × 0.65—0.8 mm, somewhat fleshy, yellow–green; staminate flowers 35+ in 5 clusters, each with pedicel–like stalk, each cluster associated with 1 bractlet, the bractlet oblanceolate, ca. 1 mm long, white, fringed, the pedicel to 1.2 mm long, short–exserted from involucre and exserting flowers sequentially; pistillate flower on stalk (gynophore), at anthesis gynophore erect, 0.8 mm long, pale green, soon after gynophore elongating and becoming recurved with maturing ovary exserted.
Staminate flower reduced to 1 stamen; stamen filaments ± 0.4 mm long, white; anther conspicuously dithecal, each sac spheroid, 0.3 mm, pale yellow, longitudinally dehiscent; pollen pale yellow.
Pistillate flower pistil 1; ovary superior, 3–lobed, 0.8 × 1 mm, yellow–green, glabrous, 3–chambered, each chamber with 1 ovule; styles 3, fused at base, horizontal, 2–branched above midpoint.
Fruit capsule, 3–seeded, 3–lobed, 1.7—2 × 2.1—2.4 mm, glabrous, elastically dehiscing along septa and chamber into 6 dry valves; pedicel ± 1.5 mm long, at maturity capsule often reflexed and touching cyathium involucre.
Seed quadrangular–ovoid, ca. 1.5 × 0.8 mm, rose beneath frosty–white, finely netted epidermis, slightly wrinkled with a few circular depressions, grooved on obtuse ridge, acute on dorsal ridge, rounded on other angles.
A. C. Gibson