Echinomastus johnsonii

(Parry ex Engelmann) E. M. Baxter

Calif. Cact., 75. 1935.

IllustratedEndemic
Basionym: Echinocactus johnsonii Parry ex Engelmann in S. Watson, Botany (Fortieth Parallel), 117. 1871 (as johnsoni)
Synonyms: Echinomastus johnsonii var. lutescens (Parish) Wiggins Neolloydia johnsonii (Parry ex Engelmann) N. P. Taylor Sclerocactus johnsonii
Treatment appears in FNA Volume 4. Treatment on page 194. Mentioned on page 192, 193.

Stems 10–25 × 7–15 cm; ribs (13–) 18–21; areoles (14–) 21–26 mm apart along ribs; areolar glands present at least seasonally. Spines 13–24 per areole, pale-yellow to grayish lavender to maroon; radial spines 9–16 per areole; abaxial (shortest) radial spine 6–19 × (0.2–) 0.4–0.6 mm; adaxial and lateral (longest) radial spines ca. 27–40 mm; central spines 4–9 per areole, present at all ages, 27–41 × (0.7–) 1.1–1.4 mm; longest central spine straight to strongly decurved; abaxial central spine porrect, ca. 27–40 mm Flowers 4–6.5 × 4–7.7 cm; inner tepals yellow or pink to magenta, basal portions blotched with maroon, 2.5–3.7 × 1–1.8 cm; stigma lobes yellowish white to green. Fruits dehiscent only along single, longitudinal split, ± spheric, 17–18 mm. 2n = 22.


Phenology: Flowering (Feb-)Mar–May; fruiting Apr–Jun.
Habitat: Mojave desert scrub and upper edge of Sonoran desert scrub, rocky slopes, gravelly hills
Elevation: 500-1400 m

Distribution

V4 362-distribution-map.gif

Ariz., Calif., Nev., Utah.

Discussion

Echinomastus johnsonii varies geographically in both flower and spine color. The yellow-flowered plants have been named E. johnsonii var. lutescens. The pink-flowered plants occur in separate populations, as far as is known, to the north of the yellow-flowered plants, but the interface between the two forms is poorly understood.

Selected References

None.

Lower Taxa

None.
... more about "Echinomastus johnsonii"
2.7 cm27 mm <br />0.027 m <br /> (4 cm40 mm <br />0.04 m <br />) +
2.7 cm27 mm <br />0.027 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
2.7 cm27 mm <br />0.027 m <br /> (4.1 cm41 mm <br />0.041 m <br />) +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
cushionlike +
circular to linear +
1.4 cm14 mm <br />0.014 m <br /> (2.1 cm21 mm <br />0.021 m <br />) +
deciduous +  and persistent +
hourglass--shaped +
2.1 cm21 mm <br />0.021 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
Allan D. Zimmerman +  and Bruce D. Parfitt +
(Parry ex Engelmann) E. M. Baxter +
hardened +
blotched with maroon +
2.5 cm25 mm <br />0.025 m <br /> (3.7 cm37 mm <br />0.037 m <br />) +
Echinocactus johnsonii +
triangular +
curved +  and straight +
proliferating +
flattened +  and cylindric +
mucilaginous +
firm +  and hard +
connected +
divided +  and notched +
Ariz. +, Calif. +, Nev. +  and Utah. +
500-1400 m +
not separating +
4 cm40 mm <br />0.04 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 />) +
4cm;7.7cm +
pink;dull;brown;pink;dull;brown;green +
persistent +, long +  and deciduous +
6mm;20mm +
spheric +
1.7 cm17 mm <br />0.017 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
succulent +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
obscured +  and obliterated +
Mojave desert scrub and upper edge of Sonoran desert scrub, rocky slopes, gravelly hills +
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 +
deciduous +  and persistent +
Flowering (Feb-)Mar–May +  and fruiting Apr–Jun. +
mucilaginous +
ridgelike +  and nipple--shaped +
Calif. Cact., +
1 +  and 20 +
triangular +
arillate +  and strophiolate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
hemispheric;spheric +
Illustrated +  and Endemic +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
pale-yellow +  and grayish lavender +
curved +  and straight +
deciduous +  and persistent +
6mm +  and 19mm +
9 (?) +  and 16 (?) +
annulate-ridged +, hairlike +, daggerlike +, subulate +  and acicular +
0.3 cm3 mm <br />0.003 m <br /> (3.7 cm37 mm <br />0.037 m <br />) +
hard +  and rigid +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
decurrent +
unsegmented +
10cm;25cm +
cylindric +, ovoid +  and spheric +
succulent +
7cm;15cm +
yellowish white +  and green +
tuberculate +
Echinomastus johnsonii var. lutescens +, Neolloydia johnsonii +  and Sclerocactus johnsonii +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Echinomastus johnsonii +
Echinomastus +
species +
undulate +  and entire +
dull +  and glossy +
epiphytic;epiphytic;epiphytic +
not deep-seated +
barrel-shaped +  and spheric +