Echinocereus rigidissimus var. rigidissimus

Treatment appears in FNA Volume 4. Treatment on page 174. Mentioned on page 172.

Plants unbranched (very rarely few branched). Stems erect, short cylindric, 6–18 (–30) × 9–11 cm; ribs (15–) 18–23 (–26), crests slightly undulate; areoles 3–5 mm apart. Spines 15–23 per areole, all radial, straight or slightly curved toward stem, tightly appressed, pectinately arranged, bright pink or pink-and-white in alternating bands of color around stem, 6–10 mm. Flowers 6–8 × 6–9 cm; flower tube to 30 × 15–45 mm; flower tube hairs to 2 mm; inner tepals bright-rose-pink or magenta, conspicuously white banded proximally, 40–50 × 10–15 mm, tips relatively thin, delicate; anthers yellow nectar chamber 3–5 mm. Fruits greenish or dark purplish brownish, 2.5–5 cm, pulp white. 2n = 22.


Phenology: Flowering late spring–summer (May–Jul); fruiting 3 months after flowering.
Habitat: Gravelly hills, steep canyonsides, semidesert grasslands, oak woodlands, interior chaparral, igneous substrates
Elevation: 1200-1600 m

Distribution

V4 332-distribution-map.gif

Ariz., N.Mex., Mexico (Chihuahua), Mexico (Sonora)

Discussion

Echinocereus rigidissimus, lacking central spines, belongs to the E. reichenbachii group, unrelated to the superficially similar E. pectinatus group, which has at least microscopically visible stubs of central spines. It sometimes occurs with E. pseudopectinatus but without evidence of hybridization. The reported habitat preference for limestone (L. D. Benson 1969) is erroneous; this species is a calcifuge, preferring soils poor in lime and usually acid.

Selected References

None.

Lower Taxa

None.

"thin" is not a number.

cushionlike +
circular to linear +
deciduous +  and persistent +
hourglass--shaped +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Allan D. Zimmerman +  and Bruce D. Parfitt +
(Engelmann) F. Haage +
alternating +
hardened +
Cereus pectinatus var. rigidissimus +
triangular +
curved +  and straight +
variously angled +  and flattened +
proliferating +
flattened +  and cylindric +
mucilaginous +
undulate +
Ariz. +, N.Mex. +, Mexico (Chihuahua) +  and Mexico (Sonora) +
1200-1600 m +
not separating +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
6 cm60 mm <br />0.06 m <br /> (8 cm80 mm <br />0.08 m <br />) +
unisexual +  and bisexual +
2.6 cm26 mm <br />0.026 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0 cm0 mm <br />0 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
brownish;dark purplish;greenish +
dehiscent +  and indehiscent +
persistent +, long +  and deciduous +
spheric +  and narrowly obovoid +
2.5 cm25 mm <br />0.025 m <br /> (5 cm50 mm <br />0.05 m <br />) +
Gravelly hills, steep canyonsides, semidesert grasslands, oak woodlands, interior chaparral, igneous substrates +
4 cm40 mm <br />0.04 m <br /> (5 cm50 mm <br />0.05 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 +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
smooth +  and tuberculate +
deciduous +  and persistent +
Flowering late spring–summer (May–Jul) +  and fruiting 3 months after flowering. +
mucilaginous +
ridgelike +  and nipple--shaped +
Special Preisverz., +
triangular +
arillate +  and strophiolate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
rugose +  and tuberculate +
spheric;obovoid +
tuberculate +
Illustrated +
arranged +  and radial +
0 cm0 mm <br />0 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
4 cm40 mm <br />0.04 m <br /> (5 cm50 mm <br />0.05 m <br />) +
pink-and-white +  and bright pink +
curved +  and straight +
deciduous +
3mm +  and 150mm +
15 (?) +  and 23 (?) +
roughened +  and smooth +
acicular +  and subulate +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
decurrent +
unsegmented +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
yellow-green +  and dark green +
6cm;18cm +
cylindric +
0 cm0 mm <br />0 m <br /> (40 cm400 mm <br />0.4 m <br />) +
succulent +
9cm;11cm +
yellowish green +  and green +
tuberculate +
Echinocereus pectinatus var. rigidissimus +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Echinocereus rigidissimus var. rigidissimus +
Echinocereus rigidissimus +
variety +
dull +  and glossy +
0 cm0 mm <br />0 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
epiphytic;epiphytic;epiphytic +
decumbent +, pendent +, sprawling +, ascending +  and erect +
barrel-shaped +  and spheric +