Texas Yucca

Yucca rupicola is endemic to southeastern Edwards Plateau. It is the only species in the flora with flaccid, twisted leaves.

Plants usually forming open colonies of rosettes, acaulescent, with branching subterranean caudices; rosettes 2–15 per colony, each rosette with fewer than 100 leaves. Leaf blade lanceolate, twisted, strongly concave, widest at middle, distinctly narrowing toward base, broadened at stem attachments, 35–60 × 1.7–4 cm, somewhat fleshy, flexible, margins denticulate or wavy, dark orange or reddish brown, apex pointed. Inflorescences paniculate, arising beyond rosettes, narrowly ovoid, 2.5–10 dm; branches 0.7–2 dm; bracts erect; peduncle scapelike, 0.3–1.5 m, 1.5–2 cm diam. Flowers pendent; perianth campanulate; tepals distinct, white or greenish white, ovate, 4–7 × 1.5–3 cm, apex sharply acuminate; filaments 1.8–3.2 cm; pistil 2.5–4.5 cm; style white or greenish, 12–20 mm; stigmas lobed. Fruits erect, capsular, dehiscent, ellipsoid to cylindric, 4–5.5 × 2–3 cm, dehiscence septicidal. Seeds dull black, thin, 6–8 mm diam.

Tex.

Flowering late spring.

Rocky hillsides of limestone ledges, open plains, woodlands; 400--900m.

Yucca rupicola var. tortifolia Engelmann

Yucca rupicola is a plant in the family Asparagaceae, known as the twistleaf yucca, twisted-leaf yucca, Texas yucca or twisted-leaf Spanish-dagger. The species was described by George Heinrich Adolf Scheele in 1850. This is a small, acaulescent plant with distinctive twisted leaves. It is native to the Edwards Plateau region of Texas and also to northeastern Mexico (Coahuila, Nuevo León).

Yucca rupicola forms colonies of rosettes, lacking trunks above-ground but producing a branched caudex under the surface. Leaves are narrowly lanceolate, slightly succulent, twisted, up to 60 cm long but about 40 mm wide at its widest point. Flowers are pendant (drooping), bell-shaped, white or greenish. Fruit is a dry capsule up to 6 cm long.