Rep. U.S. Geogr. Surv., Wheeler, 272. 1878.
Plants robust, with large crowns, to 40 cm diam.; trunks to 1.5 m, usually reclining. Leaves stout, rigid; blade whitish or bluish green, 35–100 × 2–3 cm wide above broadened base, densely waxy-glaucous, papillose, dull; prickles all antrorse. Inflorescences often massive, to 5 m; stalk 3–6 diam. at base; branches lateral, pendent in fruit, 3–10 cm; bracts wedge-shaped, attenuate; fascicles of flowers spreading, 10–20 cm from base to tip; primary axes 4–14 cm. Flowers with receptacles 0.2–0.5 mm; tepals sometimes tinged purple, 2.4 × 1–1.5 mm; style 0.2–0.3 mm, becoming swollen and golden brown in fruit; stigma lobes 0.4 mm; pedicel 3–3.5 mm in fruit. Capsules broadly obovoid or rounded in cross section, not indented, 5–8 × 4–5(–7) mm; distal wing lobes 2–2.5 mm, often indented on side. 2n = 38.
Phenology: Flowering mostly late May–Jun.
Habitat: Open, rocky slopes
Elevation: 1200–1900 m
Ariz., N.Mex., Tex., Mexico (Chihuahua, Sonora).
Morphologically, Dasylirion wheeleri is fairly uniform within its range in the United States, with some minor variation in fruit size and receptacle length.