Yucca madrensis

Gentry

Agave Fam. Sonora, 159, fig. 62. 1972.

Common names: Sierra Madre yucca
Treatment appears in FNA Volume 26. Treatment on page 428. Mentioned on page 424.

Plants solitary, caulescent, shorter than 3 m. Stems 1, simple, unbranched, shorter than 2 m. Leaf-blade erect to reflexing with age, bluish-glaucous or green to yellow-green, thin, flat to conduplicate, flexible, margins entire or occasionally filiferous with slender fibers, brown to grayish, smooth. Inflorescences erect, paniculate, somewhat open, arising 1/4–1/2 within rosettes, elongate-ovoid, to 8 dm, sparsely pubescent. Flowers pendent, 3.5 cm; perianth ovoid; tepals distinct, or barely connate basally, white, ovatelanceolate to lanceolate, ca. 3 × 1.4 cm; filaments ca. 1.5 cm, glabrous; pistil 1.5–4 cm; ovary ca. 2.5 cm. Fruits becoming pendent, baccate, indehiscent, 6–12.5 × 2.5–3.8 cm, fleshy, succulent. Seeds gray, 7–10 mm diam., 5–8 mm thick.


Phenology: Flowering in summer with rains.
Habitat: Madrean pine-oak forest
Elevation: 1400–1600 m

Distribution

V26 876-distribution-map.jpg

Ariz., Mexico (Chihuahua), Mexico (Sonora)

Discussion

Yucca madrensis is closely related to Y. jaliscensis to the south and the Y. schottii complex to the north. We follow L. W. Lenz and M. A. Hanson (2000b), who have determined that plants with long, wide, flexible, blue leaves that are now usually identified as Y. schottii Engelmann (not congruent with Engelmann’s original description) are more correctly referred to Y. madrensis. Lenz and Hanson further suggested that what is now called Y. schottii represents a hybrid complex among Y. baccata, Y. elata, and Y. madrensis. This putative hybridization is conjectural, and without firm evidence we are uncertain as to the appropriate disposition of the name Y. schottii. We are somewhat skeptical of the potential for crosses between baccate species (Y. baccata and Y. madrensis) and capsular species (Y. elata).

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.

... more about "Yucca madrensis"
longitudinal +
glandular-pubescent +  and glandular +
sharp-pointed +
William J. Hess +  and R. Laurie Robbins +
Gentry +
elliptic +, ovate +, oblanceolate +, lanceolate +  and linear +
expanded +
fleshy +  and rigid +
reflexed +, erect +  and ascending +
scale-like +
Sierra Madre yucca +
Ariz. +, Mexico (Chihuahua) +  and Mexico (Sonora) +
1400–1600 m +
elongated +
flattened +
1.5 cm15 mm <br />0.015 m <br /> (?) +
broadened +
3.5 cm35 mm <br />0.035 m <br /> (?) +
indehiscent +
6 cm60 mm <br />0.06 m <br /> (12.5 cm125 mm <br />0.125 m <br />) +
succulent +  and fleshy +
2.5 cm25 mm <br />0.025 m <br /> (3.8 cm38 mm <br />0.038 m <br />) +
Madrean pine-oak forest +
arising +  and erect +
1/4 +  and 1/2 +
elongate-ovoid +
erect +  and reflexing +
green to yellow-green +  and bluish-glaucous +
long-lived +  and annual +
filiferous +  and entire +
dentate +, serrulate +  and entire +
brown +  and grayish +
denticulate +  and entire +
6-lobed +
2.5 cm25 mm <br />0.025 m <br /> (?) +
not +  and articulate +
semisucculent +
Flowering in summer with rains. +
oblong-cylindrical +  and obovoid +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
Agave Fam. Sonora, +
0 cm0 mm <br />0 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
ovate +, obovate +, round +  and flattened +
5mm +  and 8mm +
exserted +  and included +
unbranched +  and simple +
aboveground +  and subterranean +
2 cm20 mm <br />0.02 m <br /> (?) +
white;pale green +
1 +  and 3 +
list +  and count +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
white +  and dark green +
exserted +  and included +
Clistoyucca +  and Samuela +
Yucca madrensis +
species +
connate +  and distinct +
ovatelanceolate +  and lanceolate +
aboveground +  and subterranean +
polygamodioecious +, dioecious +, monoecious +, polycarpic +  and monocarpic +
small;gigantic +
petal-like +