The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links
Pediocactus nigrispinus

black-spine snowball cactus, Columbia Plateau cactus, dark-spine ball cactus, snowball cactus

Despain footcactus, Despain's pincushion cactus, San Rafael cactus

Habit Plants typically branched. Plants typically unbranched.
Stems

depressed-ovoid to elongate-ovoid, 5–30 × 5–15 cm;

areoles oval, villous.

subglobose to obovoid, 3.8–6 × 3–9.5 cm;

areoles circular to oval, villous to glabrate.

Spines

smooth, hard and rigid, distinguishable as radial and central;

radial spines 10–30 per areole, spreading at right angles to tubercles, nearly straight, white to dull reddish brown, 8–20 mm;

central spines 6–12 per areole, widely spreading or nearly erect, reddish brown to nearly black, rigid, straight or slightly curved, base yellow or cream, 15–35 mm, less than 1 mm diam. at base.

smooth, relatively hard, all radial, 9–15 per areole, spreading, white, 2–6 mm.

Flowers

1–3.5 × 2.5–5 cm;

scales and outer tepals of flower tube minutely toothed, laciniate, or entire and undulate;

outer tepals with greenish brown midstripes, oblong-cuneate, 12–25 × 4.5–9 mm;

inner tepals white, pink, magenta, yellow, or yellow-green, 19–27 × 5–10 mm.

1.5–2.5 × 1.8–2.5 cm;

scales and outer tepals minutely toothed to entire and undulate;

outer tepals yellow-bronze to peach-bronze or pink with purple midstripes, 4–10 × 3–6 mm;

inner tepals yellow-bronze to peach-bronze (rarely pink), 6–12 × 4–6 mm.

Fruits

green tinged with red, drying reddish brown, short cylindric, 6–11 × 5–10 mm.

green, drying reddish brown, turbinate, 9–11 × 10–12 mm.

Seeds

gray to black, 2–3 × 1.5–2 mm, papillate but not rugose.

black, 3.5 × 2.5 mm, shiny, papillate and rugose.

Pediocactus nigrispinus

Pediocactus despainii

Phenology Flowering spring. Flowering spring.
Habitat Great Basin desert scrub, sagebrush, grasslands, coniferous forests Desert pavements of cobble or pebble in pinyon-juniper woodlands
Elevation 400-2000 m (1300-6600 ft) 1500-1800 m (4900-5900 ft)
Distribution
from FNA
ID; OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
UT
[BONAP county map]
Discussion

No known morphologic character supports the taxonomic recognition of infraspecific taxa within Pediocactus nigrispinus. Characteristics used to distinguish the three described subspecies almost completely overlap. Pediocactus nigrispinus has been referred to P. simpsonii var. robustior (J. M. Coulter) L. D. Benson, which remains well within the range of variation for P. simpsonii. An unpublished study by J. M. Porter et al. of noncoding chloroplast DNA sequences shows P. simpsonii is less closely related to P. nigripsinus than to P. knowltonii, P. winkleri, and P. despainii.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Of conservation concern.

Population-level studies of chloroplast DNA (J. M. Porter et al. unpubl.) confirm a close relationship between Pediocactus despainii and P. winkleri. Genetic relationships among populations correspond to geographic features of the region: populations with the San Rafael Swell represent one group of related populations, and populations south of the San Rafael Swell represent another group of related populations. This pattern conflicts in some ways with morphology. While all of the populations south of the San Rafael Swell are classified as P. winkleri, within the Swell some populations are P. despainii, several are P. winkleri, and a few are morphologically intermediate.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 4. FNA vol. 4, p. 216.
Parent taxa Cactaceae > subfam. Cactoideae > Pediocactus Cactaceae > subfam. Cactoideae > Pediocactus
Sibling taxa
P. bradyi, P. despainii, P. knowltonii, P. paradinei, P. peeblesianus, P. sileri, P. simpsonii, P. winkleri
P. bradyi, P. knowltonii, P. nigrispinus, P. paradinei, P. peeblesianus, P. sileri, P. simpsonii, P. winkleri
Synonyms P. simpsonii var. nigrispinus, P. nigrispinus var. beastonii, P. nigrispinus subsp. beastonii, P. nigrispinus subsp. puebloensis Pediocactella bradyi var. despainii, P. bradyi subsp. despainii, P. bradyi var. despainii
Name authority (Hochstätter) Hochstätter: Succulenta (Netherlands) 71: 99. (1992) S. L. Welsh & Goodrich: Great Basin Naturalist 40: 83, fig. 5. (1980)
Web links