Grusonia grahamii

Shrubs, forming mats, 8–20 cm. Roots tuberlike, 9 × 2 cm. Stem segments cylindric, curved and narrowed at base, 3–7 × 1.5–3.5 cm; tubercles narrow, 10–15 mm; areoles 3 mm in diam.; wool white to yellowish. Spines (6–)8–15 per areole, mostly in distal areoles, white, yellow, tan, or red-brown, longest 3–5.5 cm; major 2–3 abaxial spines erect and red-brown, marginal spines deflexed and whitened, angular-flattened to subterete; longest central abaxial spine usually brownish, with whitish wavy lines, usually straight; major 2–5 adaxial spines divergent, ascending, rich red-brown, ± terete. Glochids increasing in number toward base of stem segments, adaxial in areole, white to yellow, to 6 mm. Flowers: inner tepals bright yellow, 20–25 mm; filaments yellow-green; style and stigma lobes cream. Fruits yellowish, cylindric to ellipsoid, 20–35 × 12–20 mm, fleshy, spineless, yellow glochidiate; areoles 35–45. Seeds yellow, 4–5 × 3–4 mm, smooth (or with 1–2 broad bumps per side). 2n = 44.

Phenology: Flowering late spring (May–Jun).
Habitat: Chihuahuan Desert, sandy, gravelly bajadas and flats
Elevation: 700-1500 m

N.Mex., Tex., Mexico (Chihuahua, Durango).

Discussion

Selected References

None.

Lower Taxa