Coryphantha echinus

(Engelmann) Britton & Rose

Cact. 4: 42. 1923.

Common names: Sea-urchin cactus rhinocerous cactus
Basionyms: Mammillaria echinus Engelmann Proc. Amer. Acad. Arts 3: 267. 1856 (as Mamillaria)
Synonyms: Coryphantha cornifera var. echinus (Engelmann) L. D. Benson Coryphantha pectinata (Engelmann) Britton & Rose Mammillaria pectinata Engelmann
Treatment appears in FNA Volume 4. Treatment on page 227. Mentioned on page 222, 228.

Plants usually unbranched (branched with age, forming large clumps to 80 cm diam. at low elevation in Brewster County, Texas), usually relatively smooth except for protruding abaxial central spine, stem largely obscured by spines. Roots diffuse or short taproots. Stems spheric (ovoid or conic with age) to cylindric, 3–15 (–20) × 3–7.6 cm; tubercles 8–12 × 6–11 mm, firm; areolar glands seasonally conspicuous; parenchyma not mucilaginous; pith 1/4–1/3 of lesser stem diam.; medullary vascular system absent. Spines 16–34 per areole, drab whitish, pale yellowish tan, or pale purplish gray, overlying relatively bright-yellow to dark yellowbrown inner layers, later gray with dark tips; radial spines 15–25 (–29) per areole, 16–24 × 0.2–0.6 mm; subcentral spines (0–) 2–3 (–4) per areole, erect; central spines (0–) 1–4 (–11) per areole, larger spines and abaxial central spine porrect, straight or slightly curved downward (rarely strongly recurved), others appressed, abaxial (or only) central spine 11.5–25 × 0.3–0.9 mm, rigid, others slightly longer and thinner. Flowers nearly apical, 25–65 × 25–65 mm; outer tepals entire; inner tepals 20–37 per flower, bright-yellow, sometimes proximally reddish, 22–34 × 4.5–12 mm; outer filaments reddish, reddish orange, or yellow; anthers bright yellow-orange; stigma lobes 10–13, whitish or greenish yellow, 3–4 mm. Fruits green, ovoid, 12–28 × 10–19 mm, slimy; floral remnant strongly persistent. Seeds reddish-brown, somewhat comma-shaped, 1.7–1.9 mm, smooth, shiny. 2n = 22 (as C. cornifera var. echinus).


Phenology: Flowering late spring–summer (Apr–Jul); fruiting 2-4 months after flowering.
Habitat: Degraded grasslands, desert scrub, on and near limestone or igneous hills and benches, with Larrea
Elevation: 300-1500 m

Distribution

V4 417-distribution-map.gif

Tex., Mexico (Chihuahua), Mexico (Coahuila)

Discussion

Mature plants of Coryphantha echinus are dimorphic with respect to presence/absence of porrect (inner or abaxial) central spines. Immature plants of most populations lack central spines, except in the southern and western populations where some individuals produce central spines even before sexual maturation. The name C. pectinata (Engelmann) Britton & Rose was used for plants lacking central spines. Coryphantha echinus was recombined as variety of central Mexican C. cornifera (L. D. Benson 1969c); however, they belong to different species groups.

The showy flowers of Coryphantha echinus are among the most ephemeral in the Cactaceae. They are fully expanded at high noon (if in brilliant sunlight) and wilt after only an hour or two. By mid afternoon, when most Chihuahuan Desert cacti are at the peak of anthesis, the flowers of C. echinus are tightly closed.

Selected References

None.

Lower Taxa

None.

"thinner" is not a number.

... more about "Coryphantha echinus"
1.15 cm11.5 mm <br />0.0115 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
bright yellow-orange +
cushionlike +
circular to linear +
deciduous +  and persistent +
connected +
hourglass--shaped +
Allan D. Zimmerman +  and Bruce D. Parfitt +
(Engelmann) Britton & Rose +
spineless +  and naked +
hardened +
Mammillaria echinus +
triangular +
curved +  and straight +
0.4 cm4 mm <br />0.004 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
proliferating +
flattened +  and cylindric +
Sea-urchin cactus +  and rhinocerous cactus +
with mucilage +  and mucilaginous +
Tex. +, Mexico (Chihuahua) +  and Mexico (Coahuila) +
300-1500 m +
not separating +
2.5 cm25 mm <br />0.025 m <br /> (6.5 cm65 mm <br />0.065 m <br />) +
15 cm150 mm <br />0.15 m <br /> (30 cm300 mm <br />0.3 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (15 cm150 mm <br />0.15 m <br />) +
25mm;65mm +
indehiscent +
persistent +, long +  and deciduous +
12mm;28mm +
fleshy +  and juicy +
1 cm10 mm <br />0.01 m <br /> (1.9 cm19 mm <br />0.019 m <br />) +
Degraded grasslands, desert scrub, on and near limestone or igneous hills and benches, with Larrea +
gray +, bright-yellow to dark yellowbrown +  and bright-yellow +
2.2 cm22 mm <br />0.022 m <br /> (3.4 cm34 mm <br />0.034 m <br />) +
deciduous +  and persistent +
rudimentary +
flat +  and terete +
nearly +  and microscopic +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
tuberculate +
fluted;spheric;depressed-spheric or club-shaped +
fringed +  and toothed +
small +
yellow +, reddish orange +  and reddish +
not mucilaginous +
deciduous +  and persistent +
Flowering late spring–summer (Apr–Jul) +  and fruiting 2-4 months after flowering. +
mucilaginous +
1/4 +  and 1/3 +
ridgelike +  and nipple--shaped +
colorless +  and white greenish or pinkish +
3;2;2;30 +
erose +  and entire +
rudimentary +
triangular +
arillate +  and strophiolate +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
comma--shaped +
adventitious +
gray +, pale purplish +, tan +, pale yellowish +  and drab whitish +
curved +  and straight +
deciduous +  and persistent +
16mm +  and 24mm +
15 (?) +  and 25 (?) +
annulate-ridged +, hairlike +, daggerlike +, subulate +  and acicular +
hard +  and rigid +
differentiated +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
decurrent +
unsegmented +
3cm;15cm +
tuberculate +
spheric +  and cylindric +
succulent +
3cm;7.6cm +
greenish yellow +  and whitish +
protruding +  and flat +
large +  and small +
tuberculate +
Coryphantha cornifera var. echinus +, Coryphantha pectinata +  and Mammillaria pectinata +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Coryphantha echinus +
Coryphantha +
species +
dull +  and glossy +
pitted +  and raised-reticulate +
8mm +  and 12mm +
conic +  and hemispheric or cylindric +
6mm +  and 11mm +
epiphytic;epiphytic;epiphytic +