Yucca rostrata

Engelmann ex Trelease

Rep. (Annual) Missouri Bot. Gard. 13: 68, plates 40–42, plate 84, fig. 3, plate 93, fig. 2. 1902.

Common names: Beaked yucca
Synonyms: Yucca rostrata var. linearis Trelease
Treatment appears in FNA Volume 26. Treatment on page 430. Mentioned on page 425, 431.

Plants solitary or forming colonies of rosettes, caulescent, arborescent, 2.5–3.6 m, not including inflorescence, 1.8–3.2 dm diam; rosettes each with more than 100 leaves. Stems 1–several, erect, mostly simple, occasionally 1–3-branched. Leaf blade linear, often twisted, flat to concavo-convex, widest considerably beyond middle, 25–60 × 1.2–1.7 cm, glaucous, smooth, margins minutely denticulate, lemon yellow, hyaline, apex spinose, spine tipped. Inflorescences paniculate, arising just within or beyond rosettes, ovoid, 3–10 dm; branches up to 3.8 dm; bracts erect; peduncle sometimes scapelike, 0.3–1 m, less than 2.5 cm diam., glabrous or glabrescent. Flowers pendent; perianth globose to campanulate; tepals distinct, white, narrowly ovate, 4.2–5.2 × 1.1–2 cm, apex sharply acuminate; filaments 1.7–2 cm; pistil 2.5–3.5 cm; style white, 6–14 mm; stigmas lobed. Fruits erect, capsular, dehiscent, ovoid to ellipsoid, rarely constricted, 4–7 × 1.8–2.5 cm, dehiscence septicidal.


Phenology: Flowering spring.
Habitat: Rocky mountain slopes, canyon bottoms
Elevation: 700 m

Distribution

V26 883-distribution-map.jpg

Tex., n Mexico (Coahuila).

Discussion

In the United States, Yucca rostrata is restricted to Brewster County, Texas. It is closely related to Y. thompsoniana (K. H. Clary 1997), which is perhaps just a northern variant of this species.

Selected References

None.

Lower Taxa

None.