Flora of North America species comparison

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Echinocereus pectinatus

Echinocereus poselgeri

Mexican comb hedgehog, rainbow cactus

dahlia hedgehog cactus, pencil cactus, sacasil
Habit Plants straggling, very tall and slender, sparingly branched at any level.
Stems

initially erect, later sprawling or clambering, long cylindric, 12–60(–130) × 0.6–1(–2) cm;

ribs 8–10, crests low, uninterrupted or shallowly undulate;

areoles 1–2–5 mm apart.
Spines

(9–)11–13(–17) per areole, stiff and straight, usually tan, brown, or black, sometimes yellow, pale pink, ashy white, or gray, sometimes black central spines contrasting with white radial spines;

radial spines 8–16 per areole, 2–5 mm;

central spines 1(–3) per areole, closely appressed (except at the stem tip), terete, 4–9 mm.
Flowers

3.5–6 × 3.5–7 cm;

flower tube 15–20 × 7–18 mm;

flower tube hairs 3–5(–10) mm;

inner tepals rose-pink with darker pink to magenta midstripes, proximally darker, 25–35 × 4–12 mm, tips relatively thin and delicate;

anthers yellow;

nectar chamber 1–4 mm.
Fruits

dark green to brownish, 2–3 cm, pulp white.
2n

= 22.

Echinocereus pectinatus

Echinocereus poselgeri
Phenology Flowering Mar–Apr; fruiting 2 1/2-3 months after flowering.
Habitat Tamaulipan thorn scrub, alluvial soils
Elevation 0-200[-1100] m (0-700[-3600] ft)
Distribution
from FNA
TX; n Mexico
[WildflowerSearch map]
[BONAP county map]
from FNA
TX; Mexico (Coahuila, Nuevo León, Tamaulipas)
[BONAP county map]
Discussion

Varieties 2 (1 in the flora).

At least in the United States, Echinocereus pectinatus (diploid) has only pink or purple flowers, unlike the polymorphic species E. dasyacanthus (tetraploid). Echinocereus pectinatus differs from the entire E. reichenbachii species group in that the areoles of its relatively thick-walled flower tube have stouter spines and much shorter hairs. Superficially similar species west of the Continental Divide, formerly associated with E. pectinatus (E. pseudopectinatus, E. rigidissimus, and some Sonoran species), are more closely related to the E. reichenbachii species group with densely bristly flower buds and delicate, ephemeral inner tepals. Echinocereus pectinatus var. pectinatus is endemic to Mexico; reports from the United States were misidentifications of var. wenigeri, E. pseudopectinatus (in Arizona), and unusually short-spined plants of E. dasyacanthus.

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

Echinocereus poselgeri, with tuberous roots and erect, slender, elongate stems, superficially resembles some Peniocereus species. The polyphyletic genus Wilcoxia Britton & Rose formerly included this species along with species of Peniocereus. The flowers, fruits, and seeds of E. poselgeri are typical for Echinocereus, quite similar to those of E. reichenbachii.

(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. engelmannii, E. enneacanthus, E. fasciculatus, E. fendleri, E. ledingii, E. nicholii, E. papillosus, 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. dasyacanthus, E. davisii, E. engelmannii, E. enneacanthus, E. fasciculatus, E. fendleri, E. ledingii, E. nicholii, E. papillosus, E. pectinatus, E. pentalophus, E. pseudopectinatus, E. reichenbachii, E. rigidissimus, E. stramineus, E. triglochidiatus, E. viridiflorus
Subordinate taxa
E. pectinatus var. wenigeri
Synonyms Echinocactus pectinatus E. tuberosus, Wilcoxia poselgeri
Name authority (Scheidweiler) Engelmann: in F. A. Wislizenus, Mem. Tour N. Mexico, 109. (1848) Lemaire: Cactées, 57. (1868)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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