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calico cactus, Engelmann's hedgehog cactus, strawberry hedgehog cactus

spiny hedgehog cactus, Texas rainbow cactus

Habit Plants 3–60-branched, ultimately forming somewhat open clumps. Plants unbranched or few branched, forming loose clumps of fewer than 20 stiff branches in old age.
Stems

mostly erect, cylindric or somewhat tapering distally, (5–)14–45(–70) × 3–9 cm;

ribs 10–13, crests slightly undulate;

areoles 6–10(–15) mm apart.

erect, ovoid, becoming cylindric with age, 11–23(–40) × (4.5–)5.5–7(–10) cm;

ribs (13–)15–19(–21), crests rather sharply undulate;

areoles 5–11 mm apart.

Spines

(8–)15–20 per areole, usually straight (curved and twisted in desert mountains and peninsular ranges of California), individual spines with broad zones of different colors: whitish or grayish, dull golden-yellow, or reddish brown to nearly black;

radial spines 6–14 per areole, 8–20(–50) mm;

central spines (2–)4–6(–9) per areole, divergent-porrect, 12–70 mm, abaxial central spine often fading whitish, flat to sharply angled (terete or nearly so in north-central Arizona).

19–28 per areole, straight, appressed (radial spines) or spreading in all directions (central spines), presenting relatively bristly appearance (except when spines very short, and then having relatively smooth appearance as in E. pectinatus), pink to pale yellow, white, or tan, less often dark brown or purplish, annual growth increments marked (often vaguely) by rings of spines with contrasting colors;

radial spines (16–)17–25(–28) per areole, 5–15(–25) mm;

central spines (2–)8–12(–15) per areole, terete, largest spines 4.5–9.5(–14) mm.

Flowers

6–9 × 5–9 cm;

flower tube 13–30 × 10–30 mm;

flower tube hairs 1 mm;

inner tepals bright rose-pink to magenta, often varying from paler to darker in same population, proximally darker, 37–75 × (8–)14–25 mm, tips relatively thin, delicate;

anthers yellow;

nectar chamber 4–6 mm.

7–8.5(–10) × 7–12 cm;

flower tube 10–20 × to 10 mm;

flower tube hairs 1–3 mm;

inner tepals either yellow (rarely orange-yellow, sometimes becoming salmon- or rose-pink with age), or rose-pink to magenta, proximal 5–30% green in either case, (25–)32–69(–77) × 8–23 mm, tips relatively thin and delicate;

anthers yellow;

nectar chamber 2–6 mm.

Fruits

red or orangish, 25–45 mm, pulp whitish becoming infused with pink or red from the skin.

dark dull purplish to maroon (sometimes remaining green), 2–3.5 cm, pulp white to purplish pink.

2n

= 44.

= 44.

Echinocereus engelmannii

Echinocereus dasyacanthus

Phenology Flowering Mar–Apr; fruiting May–Jul. Flowering Mar–May; fruiting Jun–Aug.
Habitat Sonoran and Mojave deserts, chaparral, pinyon-juniper woodlands Chihuahuan desert scrub, valleys to rocky canyonsides, limestone
Elevation 200-2400 m [700-7900 ft] 600-1500 m [2000-4900 ft]
Distribution
from FNA
AZ; CA; NV; UT; Mexico (Baja California, Sonora)
[WildflowerSearch map]
[BONAP county map]
from FNA
NM; TX; Mexico (Chihuahua, Coahuila)
[WildflowerSearch map]
[BONAP county map]
Discussion

The characteristics distinguishing Echinocereus engelmannii from E. fasciculatus to the east are poorly documented, and W. Blum et al. (1998) combined the two as separate subspecies of E. engelmannii. Historically, E. engelmannii has been characterized as having the abaxial central spine in each areole particularly long, pale, and strongly compressed dorsiventrally (sharply angled, hence daggerlike), contrasting with the other spines. In practice that trait is not always diagnostic. Plants called Echinocereus engelmannii var. acicularis L. D. Benson are essentially morphologically and geographically intermediate between those referred to E. fasciculatus and E. engelmannii var. chrysocentrus.

The history of confusion with Echinocereus nicholii has resulted in misidentification of yellow-spined individuals of E. engelmannii.

Spine color polymorphism, common within Echinocereus engelmannii, provided the original basis for varieties chrysocentrus and purpureus. The well-marked, identifiable extremes often occur in populations that include individuals easily assigned to other named varieties, or not assignable to any. L. D. Benson (1969, 1982) and subsequent authors (e.g., N. P. Taylor 1985; W. Blum et al. 1998) have attempted to recognize infraspecific taxa within E. engelmannii. However, one of those is clearly a distinct species (E. nicholii), while the remainder are either too poorly defined or too poorly known to treat fully here. At higher elevations beyond the western edge of the desert, E. engelmannii var. munzii (Parish) P. Pierce & Fosberg has been distinguished by its curving, twisting, gray spines, somewhat resembling spines of westernmost plants of E. triglochidiatus var. mojavensis. Plants of the western Sonoran Desert margin in the Mexican boundary region in California are the typical E. engelmannii var. engelmannii. Similar plants from the opposite, eastern, side of the Sonoran Desert, in Arizona, have been called E. engelmannii var. acicularis L. D. Benson. In the intervening Colorado River Valley is spinier E. engelmannii var. chrysocentrus (Engelmann & J. M. Bigelow) Rümpler. In E. engelmannii var. acicularis at the lowest altitudes, central spines are usually four, in which cases taxonomic segregation from E. engelmannii var. chrysocentrus seems arbitrary. At higher altitudes, plants of E. engelmannii var. acicularis with only one or two central spines per areole are frequent, and the abaxial central spine may be terete instead of angular and daggerlike as in E. engelmannii var. chrysocentrus. The most formidably spiny extremes of the species were segregated as E. engelmannii vars. howei and armatus; however, other individuals in the original populations (type localities) are readily assigned to E. engelmannii var. chrysocentrus. W. Blum et al. (1998) placed all of the above varieties under E. engelmannii subsp. engelmannii.

Plants smaller in all parts and with fewer central spines from north-central Arizona are Echinocereus engelmannii subsp. decumbens (Clover & Jotter) W. Blum & Mich. Lange. L. D. Benson (1969) referred those to var. variegatus (Engelmann & J. M. Bigelow) Rümpler, but the type locality of var. variegatus is in a different region. The status of E. engelmannii var. purpureus L. D. Benson remains uncertain; its similarity to unidentified diploid material found in northern Arizona suggests that it could be a separate species, but more variable than its original diagnosis allowed.

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

Flower color of Echinocereus dasyacanthus is spectacularly polymorphic. Unlike E. pectinatus var. wenigeri, however, the inner tepals are never white proximally. No hybrids are known to occur where the tetraploid E. dasyacanthus grows sympatrically with the diploid E. pectinatus, near the Pecos River. The names E. pectinatus var. neomexicanus and var. minor pertain to the hybrids with E. coccineus, E. ×roetteri, including E. ×lloydia. L. D. Benson (1969) misapplied the epithet neomexicanus to E. dasyacanthus. In Big Bend National Park, a few populations with unusually short spines are the basis for erroneous reports of E. pectinatus var. wenigeri, E. pectinatus var. pectinatus, and E. ctenoides (Engelmann) Lemaire. Reports from Arizona were apparently misidentifications of E. pseudopectinatus.

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

Source FNA vol. 4. FNA vol. 4.
Parent taxa Cactaceae > subfam. Cactoideae > Echinocereus Cactaceae > subfam. Cactoideae > Echinocereus
Sibling taxa
E. arizonicus, E. berlandieri, E. bonkerae, E. chisosensis, E. coccineus, E. dasyacanthus, E. davisii, E. enneacanthus, E. fasciculatus, E. fendleri, E. ledingii, E. nicholii, E. papillosus, E. pectinatus, E. pentalophus, E. poselgeri, E. pseudopectinatus, E. reichenbachii, E. rigidissimus, E. stramineus, E. triglochidiatus, E. viridiflorus
E. arizonicus, E. berlandieri, E. bonkerae, E. chisosensis, E. coccineus, E. davisii, E. engelmannii, E. enneacanthus, E. fasciculatus, E. fendleri, E. ledingii, E. nicholii, E. papillosus, E. pectinatus, E. pentalophus, E. poselgeri, E. pseudopectinatus, E. reichenbachii, E. rigidissimus, E. stramineus, E. triglochidiatus, E. viridiflorus
Synonyms Cereus engelmannii, E. engelmannii var. armatus, E. engelmannii var. chrysocentrus, E. engelmannii var. howei E. pectinatus var. dasyacanthus
Name authority (Parry ex Engelmann) Lemaire: Cactées, 56. (1868) Engelmann: in F. A. Wislizenus, Mem. Tour N. Mexico, 100. (1848)
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