Pediocactus sileri

(Engelmann ex J. M. Coulter) L. D. Benson

Cact. Succ. J. (Los Angeles) 33: 53. 1961.

Common names: Gypsum cactus Siler’s pincushion cactus
EndemicConservation concern
Basionym: Echinocactus sileri Engelmann ex J. M. Coulter Contr. U.S. Natl. Herb. 3: 376. 1896
Synonyms: Utahia sileri (Engelmann ex J. M. Coulter) Britton & Rose
Treatment appears in FNA Volume 4. Treatment on page 212. Mentioned on page 213, 216.

Plants few branched or unbranched. Stems depressed-ovoid or occasionally elongate-cylindric, 5–15 (–25) × 6–11.5 cm; areoles circular to pyriform, villous to lanate. Spines distinguishable as radial and central: radial spines 11–15 per areole, white, 11–21 mm; central spines 3–7 per areole, nearly porrect, brownish black aging to pale gray or white, straight or slightly curving at tips, 13–30 × 1 mm at base. Flowers 0.8–2.2 × 2–3 cm; scales long fringed; outer tepals brown with white margins, long fringed, 9–15 × 3–4.5 mm; inner tepals yellow with purple veins, 15–20 × 4.5–6 mm. Fruits greenish yellow, short cylindric, 12–15 × 6–9 mm. Seeds gray to nearly black, 3.5–5 × 3–3.5 mm, papillate and rugose.


Phenology: Flowering spring.
Habitat: Rounded hills in gypsum clay and sandy soils of Moenkopi Formation, Great Basin desert scrub
Elevation: 900-1600 m

Discussion

Of conservation concern.

Pediocactus sileri stems tend to develop a basal thatch of spines that anchor it to the fine, gypsum-rich soil. This species is endemic to a narrow strip along the Arizona-Utah border.

Selected References

None.

Lower Taxa

None.
... more about "Pediocactus sileri"
cushionlike +
circular to linear +
deciduous +  and persistent +
villous +  and lanate +
circular +  and pyriform +
Kenneth D. Heil +  and J. Mark Porter +
(Engelmann ex J. M. Coulter) L. D. Benson +
hardened +
Echinocactus sileri +
triangular +
white +, pale gray +  and brownish black +
curving +  and straight +
13mm +  and 30mm +
terete +  and flat +
1 cm10 mm <br />0.01 m <br /> (?) +
proliferating +
flattened +  and cylindric +
Gypsum cactus +  and Siler’s pincushion cactus +
mucilaginous +
Ariz. +  and Utah. +
900-1600 m +
not separating +
0.8 cm8 mm <br />0.008 m <br /> (2.2 cm22 mm <br />0.022 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 />) +
greenish yellow +
persistent +, long +  and deciduous +
12mm;15mm +
cylindric +
dry +, fleshy +  and juicy +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
Rounded hills in gypsum clay and sandy soils of Moenkopi Formation, Great Basin desert scrub +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 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 +
entire +  and fimbriate +
0.9 cm9 mm <br />0.009 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
deciduous +  and persistent +
Flowering spring. +
mucilaginous +
ridgelike +  and nipple--shaped +
Cact. Succ. J. (Los Angeles) +
greenish +  and white +
3;2;2;30 +
fringed +
thin +  and broad +
arillate +  and strophiolate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
rugose +  and papillate +
pyriform;obovoid +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Endemic +  and Conservation concern +
curved +  and straight +
deciduous +  and persistent +
6mm +  and 30mm +
recurved +, erect +  and spreading +
distinguishable +
finely puberulent +  and glabrous +
11 (?) +  and 15 (?) +
pectinate +, awl-shaped +  and hairlike +
1.1 cm11 mm <br />0.011 m <br /> (2.1 cm21 mm <br />0.021 m <br />) +
spongy +, corky +  and hard +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
decurrent +
unsegmented +
gray-green +  and green +
5cm;15cm +
elongate-cylindric +  and depressed-ovoid +
succulent +
6cm;11.5cm +
yellow +  and green +
tuberculate +
Utahia sileri +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Pediocactus sileri +
Pediocactus +
species +
dull +  and glossy +
not confluent +
mammillate +, cylindroid +, truncate-conic +, conic +  and pyramidal +
0.2 cm2 mm <br />0.002 m <br /> (1 cm10 mm <br />0.01 m <br />) +
unbranched +, branched +  and few +
epiphytic;epiphytic;epiphytic +
hanging +  and erect to prostrate +
barrel-shaped +  and spheric +