Yucca faxoniana |
Yucca madrensis |
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Eve's needle, Faxon yucca, Spanish bayonet, Spanish dagger |
Sierra madre yucca, yucca |
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Habit | Plants solitary, erect, arborescent, 2.5–6.9 m, including inflorescence. | 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. |
Stems | 1, simple or with 2–4 branches, to 5.1 m, average diam. 32 cm. |
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Leaf | blade erect, yellowish green, 43–115 × 3.1–8.4 cm, rigid, smooth, glabrous, margins conspicuous, curling, filiferous, brown. |
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Inflorescences | erect, paniculate, often with proximal branches arising beyond rosettes, broadly ovoid, 5.5–25.5 dm, glabrous; peduncle 0.3–0.6 m. Flowers pendent, 4.4–12.4 cm; perianth campanulate; tepals connate basally into floral cup 1–32 mm, white to greenish white, ovate, 3.9–10.8 cm; filaments averaging 2.2 cm from base of tepals, glabrous; anthers 1–6 mm; pistil 2.8–8 × 0.7 cm; ovary ca. 4.5–5 times longer than wide; style 4.5 mm; stigmas distinct. |
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, ovate-lanceolate to lanceolate, ca. 3 × 1.4 cm; filaments ca. 1.5 cm, glabrous; pistil 1.5–4 cm; ovary ca. 2.5 cm. |
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Fruits | pendent, baccate, indehiscent, elongate, 3.6–13.6 × 1.8–3.6 cm, fleshy, succulent. |
becoming pendent, baccate, indehiscent, 6–12.5 × 2.5–3.8 cm, fleshy, succulent. |
Seeds | black, 7.7 mm diam., 2.9 mm thick, smooth. |
gray, 7–10 mm diam., 5–8 mm thick. |
Yucca faxoniana |
Yucca madrensis |
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Phenology | Flowering late winter–spring. | Flowering in summer with rains. |
Habitat | Rocky slopes, flat plains | Madrean pine-oak forest |
Elevation | 800–2100 m (2600–6900 ft) | 1400–1600 m (4600–5200 ft) |
Distribution |
TX; Mexico (Chihuahua, Coahuila)
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AZ; Mexico (Chihuahua, Sonora)
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Discussion | Trelease described the genus Samuela based on two species, Samuela faxoniana and S. carnerosana. K. H. Clary’s DNA study (1997) shows them to be closely related but genetically distinct. Yucca faxoniana is often used for landscaping in arid and semiarid regions of Texas and New Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 26, p. 427. | FNA vol. 26, p. 428. |
Parent taxa | Agavaceae > Yucca | Agavaceae > Yucca |
Sibling taxa | ||
Synonyms | Samuela faxoniana, Y. australis, Y. macrocarpa | |
Name authority | Sargent: Man. Trees, 121. (1905) | Gentry: Agave Fam. Sonora, 159, fig. 62. (1972) |
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