Cylindropuntia acanthocarpa
buck-horn cholla
6–20(–30+) per areole, often accompanied by 0–5 short bristlelike spines at areole margins, usually in distal areoles;
major abaxial spines deflexed to divergent, subterete to flattened;
major adaxial spines ascending-divergent, terete, yellow or tan to deep red-brown, aging gray, the central spine longest, 12–30(–38) mm;
sheaths white to grayish with yellow to golden tips, baggy to tight fitting.
in inconspicuous to small adaxial tuft, yellow to brown, 0.5–2 mm.
inner tepals bright yellow to bronze to brick red, spatulate, 20–30 mm, apiculate-emarginate;
filaments red;
anthers yellow;
style and stigma lobes white to light green.
tan at maturity, obconic to ellipsoid, 15–35 × 15–20 mm, dry, tuberculate, densely to sparsely spiny (rarely spineless), with apical flange above shallow umbilicus;
basal tubercles longest;
areoles 12–30.
pale yellow to tan, angular or squarish in outline, warped, 3.5–5 × 3–4.5 mm, sides smooth, each with 2–4 large depressions;
girdle smooth.
Cylindropuntia acanthocarpa
Varieties 4 (4 in the flora).
Cylindropuntia acanthocarpa hybridizes with C. abyssi, C. echinocarpa (= C. ×deserta), C. bigelovii (= C. ×campii), C. leptocaulis (see C. ×tetracantha), C. ×multigeniculata, C. spinosior, C. versicolor, and C. whipplei (= C. congesta). Hybrids of C. acanthocarpa and C. ×multigeniculata are more open in habit, with longer stem segments than C. ×multigeniculata and with reddish filaments like C. acanthocarpa.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Tubercles 2.5-4.5 cm, broad; stem segments gray-green; spines of adjacent areoles not or barely interlaced, 6-11(-14) per areole; fruits bearing few spines or sometimes spineless | var. thornbe |
1. Tubercles (1-)1.5-2.5(-3) cm, broad to narrow; stem segments green to yellow-green; spines of adjacent areoles interlaced; fruits densely spiny, sometimes burlike | → 2 |
2. Abaxial 5-7 spines deflexed, usually subparallel, whitish to light brown; tubercles broad, oval; shrubs with few, ascending branches | var. acantho |
2. Abaxial (14-)18-30+ spines deflexed to divergent, spreading, pale yellow to red-brown; tubercles narrowly elliptic; shrubs with few to many, spreading branches | → 3 |
3. Branches usually at acute angles; stem segments yellowish green, usually long, commonly 15-30 cm; spines 18-30+, yellow to tan, sheaths baggy; inner tepals yellow | var. colorad |
3. Branches usually at obtuse angles; stem segments green to dark green, usually short, commonly 8 -20 cm; spines 14-18(-23) per areole, yellow or red-brown, sheaths tight; inner tepals yellow to bronze to brick red | var. major |
CalFlora
WildflowerSearch
iNaturalist
USDA Plants Database
