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.
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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 +