Yucca elata |
Yucca faxoniana |
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palmella, soap-tree yucca, soap-weed yucca |
Eve's needle, Faxon yucca, Spanish bayonet, Spanish dagger |
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Habit | Plants solitary or forming small colonies of rosettes, caulescent or rarely acaulescent, distinctly arborescent, mostly few-branched, 1.2–4.5 m; rosettes usually large, symmetrical or asymmetrical. | Plants solitary, erect, arborescent, 2.5–6.9 m, including inflorescence. | ||||
Stems | 1–7 per colony, erect, thick, 1–1.5(–2.5) m. Leaf blade pale green, linear, widest near middle, 25–95 × 0.2–1.3 cm, flexible, margins entire, curled, filiferous, whitish, apex tapering to short spine. |
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 | mostly paniculate, sometimes distally racemose, arising beyond rosettes, mostly narrowly ovoid to ovoid, 7–15 × 2.5–6.5 dm; branches 0.7–3.5 dm; bracts erect; peduncle sometimes scapelike, 1–2 m, 2.5–5.5 cm diam. |
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. |
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Flowers | pendent; perianth campanulate or globose; tepals distinct, creamy white, often tinged green or pink, narrow to broadly elliptic or ovate, 3.2–5.7 × 1.3–3.2 cm; filaments 1.5–2.5(–3.2) cm, pubescent; anthers (2–)2.5–4.8 mm; pistil 2–3.2 × 0.6–1 cm; style white or pale green, 6–11 mm; stigmas lobed. |
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Fruits | erect, capsular, dehiscent, oblong-cylindric, symmetrical or rarely constricted, 4–8.2 × 2–4 cm, dehiscence septicidal. |
pendent, baccate, indehiscent, elongate, 3.6–13.6 × 1.8–3.6 cm, fleshy, succulent. |
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Seeds | dull black, thin, 7–11(–14) mm diam. |
black, 7.7 mm diam., 2.9 mm thick, smooth. |
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Yucca elata |
Yucca faxoniana |
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Phenology | Flowering late winter–spring. | |||||
Habitat | Rocky slopes, flat plains | |||||
Elevation | 800–2100 m (2600–6900 ft) | |||||
Distribution |
North America; Mexico
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TX; Mexico (Chihuahua, Coahuila)
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Discussion | Varieties 2 (2 in the flora). J. L. Reveal (1977c) reduced S. D. McKelvey’s (1938–1947) Yucca utahensis and Y. verdiensis to varieties of Y. elata based primarily u!pon growth forms. J. M. Webber (1953) considered that these taxa are populations of hybrids between members of the Y. glauca alliance of the Great Plains and Y. elata of the American Southwest. Reveal believed that Webber did not provide adequate justification for his hybrid hypothesis. K. H. Clary (1997, pers. comm.) believes that Y. utahensis is genetically distinct from Y. elata and Y. verdiensis, based on DNA evidence and the morphological characters of style, stigma, fruit, and leaf. Her DNA evidence shows that Y. elata and Y. verdiensis are sister taxa, while Y. utahensis is not. Although there is a great range of variation within Y. elata as circumscribed here, the two varieties recognized are difficult to distinguish. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
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Key |
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Source | FNA vol. 26, p. 432. | FNA vol. 26, p. 427. | ||||
Parent taxa | Agavaceae > Yucca | Agavaceae > Yucca | ||||
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Subordinate taxa | ||||||
Synonyms | Samuela faxoniana, Y. australis, Y. macrocarpa | |||||
Name authority | Engelmann: Bot. Gaz. 7: 17. (1882) | Sargent: Man. Trees, 121. (1905) | ||||
Web links |