Difference between revisions of "Echinocactus texensis"

Revision as of 22:23, 16 December 2019

Plants unbranched (very rarely branched). Stems pale gray-green (desert populations) to grass green (eastern populations), above-ground portion flat-topped, hemispheric in old age but usually deep-seated, flush with soil surface, 10–30 × 10–30 cm; ribs 13–27, very prominent, straight, vertical, or sinuous on desiccated plants, crests ± sharp, without depressions between areoles but sometimes areoles recessed part way into rib. Spines (6–)7–8 per areole, mostly decurved or 1 porrect and straight, pale tan, pink, reddish to gray, terete to flattened, annulate, not hiding stem surfaces, minutely canescent with laterally compressed unicellular trichomes; radial spines (5–)6–7 per areole; central spine 1 per areole, porrect or descending, straight or distally decurved, (20–)40–60(–80) × 1.5–4(–8) mm. Flowers 5–6 × 5–6 cm; inner tepals bright rose-pink to pale silvery-pink, proximally orange to red, (15–)28–32 × (3–)6(–9) mm, margins usually erose; stigma lobes pink to pinkish white. Fruits indehiscent (rarely rupturing irregularly), scarlet or crimson, spheric to ovoid, 15–50 × 15–40 mm, fleshy, surfaces not hidden by widely spaced hairs in axils of scales; scales 13–21, distal scales spine-tipped, minutely puberulent. Seeds black, spheric-reniform or irregularly obovoid, 2.5–3 mm, glossy; testa cells flat or very slightly convex. 2n = 22.

Phenology: Flowering late spring.
Habitat: Chihuahuan Desert, grasslands, openings in oak woodlands, Tamaulipan thorn scrub, deep soils, saline flats, low limestone hills
Elevation: 0-1400 m

N.Mex., Tex., Mexico (Coahuila, Durango, Nuevo León, Tamaulipas).

Discussion

The western, desert populations of Echinocactus texensis, unlike the eastern plants, have longer central spines that project stiffly outward and can flatten off-road vehicle tires or seriously injure a large mammal stepping on them. A dense cover of ephemeral herbs or shallow blanket of snow can hide this species completely from view.

Selected References

None.

Lower Taxa