Yucca arkansana |
|
---|---|
Arkansas yucca |
|
Habit | Plants forming small colonies, acaulescent or caulescent; rosettes usually small. |
Stems | decumbent, short, to 0.2 m. Leaf blade mostly yellowish green, flattened, grasslike, concavo-convex, widest near middle, 20–60(–70) × 0.7–2(–2.5) cm, flexible, margins entire, curled, filiferous, apex long, tapering to short spines 1.6–3.2 mm. |
Inflorescences | racemose, occasionally paniculate proximally, arising within rosettes or at rosette level, 3–6(–8) dm, glabrous; bracts erect; peduncle scapelike, 0.2–0.5(–0.6) m, 0.3–0.7(–1.3) cm diam. |
Flowers | pendent; perianth globose; tepals distinct, greenish white, elliptic to orbicular or oblong, 3.2–6.5 × 2–5 cm; filaments 1.3–2.5 cm; anthers 3.2 mm; pistil 2.5–2.8(–3.2) cm; style dark green, 7–13 mm, tumid; stigmas lobed. |
Fruits | erect, capsular, dehiscent, oblong-cylindric to obovoid, constricted near middle, stout, 4–6.5(–7) × 2–3 cm, dehiscence septicidal. |
Seeds | dull black, thin, ca. 1 cm diam. |
Yucca arkansana |
|
Phenology | Flowering spring. |
Habitat | Gravelly soil, limestone outcrops, rocky hillsides, prairies |
Elevation | 100–400 m (300–1300 ft) |
Distribution |
AR; KS; MO; OK; TX
|
Discussion | Yucca arkansana shows considerable variation, particularly in the eastern part of its range. S. D. McKelvey (1938–1947) described var. paniculata and suggested that it is an eastern extension of the species with a taller, paniculate, and pubescent inflorescence. Yucca arkansana approaches Y. louisianensis, which we have reduced to synonymy under Y. flaccida. K. H. Clary’s (1997) DNA consensus tree places Y. arkansana and Y. louisianensis adjacent to one another. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 26, p. 436. |
Parent taxa | Agavaceae > Yucca |
Sibling taxa | |
Synonyms | Y. angustifolia var. mollis, Y. arkansana var. paniculata, Y. glauca var. mollis |
Name authority | Trelease: Rep. (Annual) Missouri Bot. Gard. 13: 63. (1902) |
Web links |