Epithelantha bokei

L. D. Benson

Cact. Succ. J. (Los Angeles) 41: 185, figs. 2, 3(lower). 1969.

Synonyms: Epithelantha micromeris var. bokei (L. D. Benson) Glass & R. A. Foster
Treatment appears in FNA Volume 4. Mentioned on page 240.

Plants unbranched (very rarely branched), appearing pure white or slightly yellowish, smooth, and shiny in general aspect. Stems flat-topped, disk-shaped, short cylindric, or cylindric, 2–5 cm diam. Spines (40–) 50–90 per areole, in more than 3 superimposed series; mature lateral spine clusters uniformly white to creamy yellow, 2–2.5 (–4) mm diam.; longest intact spines 4.5–7 mm; worn spines 0.1–2 mm. Flowers conspicuously exserted beyond longer spines at stem apex, 1–1.7 × 1–1.7 cm; inner tepals 13–21 per flower, 5–6 (–9) × 1.5–2.3 (–3) mm; stamens 20–40.2n = 22.


Phenology: Flowering spring–early summer (May–Jun); fruiting summer–fall.
Habitat: Chihuahuan Desert on rocky, barren hills of sedimentary substrates
Elevation: 700[-1400] m

Discussion

Epithelantha bokei is an obligate outcrosser. Its flowers tend to open in mid afternoon, when those of E. micromeris are already closing.

Epithelantha bokei is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

None.

Lower Taxa

None.
... more about "Epithelantha bokei"
cushionlike +
elliptic +  and circular +
deciduous +  and persistent +
hourglass--shaped +
Allan D. Zimmerman +  and Bruce D. Parfitt +
L. D. Benson +
hardened +
triangular +
not protruding +
proliferating +
flattened +  and cylindric +
not mucilaginous +
Tex. +  and Mexico (Coahuila) +
700[-1400] m +
not separating +
1 cm10 mm <br />0.01 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
inconspicuous +
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 />) +
1cm;1.7cm +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
indehiscent +
persistent +, long +  and deciduous +
3mm;20mm +
cylindric +
papery +  and succulent +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Chihuahuan Desert on rocky, barren hills of sedimentary substrates +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
1.5mm;2.3mm +
uniformly white +  and creamy yellow +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 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 +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
erose-denticulate +
deciduous +  and persistent +
Flowering spring–early summer (May–Jun) +  and fruiting summer–fall. +
not mucilaginous +
0.6 cm6 mm <br />0.006 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
ridgelike +  and nipple--shaped +
Cact. Succ. J. (Los Angeles) +
3;2;2;30 +
triangular +
arillate +  and strophiolate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
hemispheric +
1 cm10 mm <br />0.01 m <br /> (?) +
superimposed +
white +  and ashy gray +
straight +
deciduous +  and persistent +
not distinguishable +
50 (?) +  and 90 (?) +
roughened +  and smooth +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
hard +  and rigid +
innocuous +
decurrent +
unsegmented +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
1cm;4cm +
cylindric +, short +, disk--shaped +  and flat-topped +
succulent +
2cm;4cm +
tuberculate +
Epithelantha micromeris var. bokei +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Epithelantha bokei +
Epithelantha +
species +
convex +  and flat +
dull +  and glossy +
not confluent +
cylindric +, short +  and hemispheric +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
yellowish +  and white +
epiphytic;epiphytic;epiphytic +
not deep-seated +
barrel-shaped +  and spheric +