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

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.

"thick" is not a number. "thin" is not a number."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property. "dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

... more about "Yucca rostrata"
longitudinal +
spine-tipped +  and spinose +
glandular-pubescent +  and glandular +
acuminate +
William J. Hess +  and R. Laurie Robbins +
Engelmann ex Trelease +
elliptic +, ovate +, oblanceolate +, lanceolate +  and linear +
expanded +
fleshy +  and rigid +
scale-like +
Beaked yucca +
Tex. +  and n Mexico (Coahuila) +
elongated +
pubescent +  and glabrous +
flattened +
1.7 cm17 mm <br />0.017 m <br /> (2 cm20 mm <br />0.02 m <br />) +
broadened +
septicidal +, 1.8cm +  and 2.5cm +
ovoid +  and ellipsoid +
constricted +
fleshy +  and dry +
Rocky mountain slopes, canyon bottoms +
beyond rosettes +  and arising +
25 cm250 mm <br />0.25 m <br /> (60 cm600 mm <br />0.6 m <br />) +
flat +  and concavo-convex +
long-lived +  and annual +
dentate +, serrulate +  and entire +
hyaline +  and lemon yellow +
denticulate +
1.2cm;1.7cm +
6-lobed +
not +  and articulate +
0 cm0 mm <br />0 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
glabrescent +  and glabrous +
30 cm300 mm <br />0.3 m <br /> (100 cm1,000 mm <br />1 m <br />) +
globose +  and campanulate +
semisucculent +
Flowering spring. +
oblong-cylindrical +  and obovoid +
2.5 cm25 mm <br />0.025 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
Rep. (Annual) Missouri Bot. Gard. +
0 cm0 mm <br />0 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
gray +  and black +
ovate +, obovate +, round +  and flattened +
exserted +  and included +
1-3-branched +  and simple +
aboveground +  and subterranean +
1 +  and several +
white;pale green +
1 +  and 3 +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
exserted +  and included +
0.6 cm6 mm <br />0.006 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
Yucca rostrata var. linearis +
Yucca rostrata +
species +
distinct +
4.2cm +  and 5.2cm +
1.1cm;2cm +
aboveground +  and subterranean +
polygamodioecious +, dioecious +, monoecious +, polycarpic +  and monocarpic +
small;gigantic +
petal-like +