Coryphantha minima

Baird

Amer. Bot. (Binghamton) 37: 150. 1931.

Common names: Nellie’s pincushion cactus
IllustratedEndemicConservation concern
Synonyms: Coryphantha nellieae Croizat Escobaria minima (Baird) D. R. Hunt Escobaria nellieae (Croizat) Backeberg Mammillaria nellieae (Croizat) Croizat
Treatment appears in FNA Volume 4. Treatment on page 233. Mentioned on page 220, 222, 228.

Plants usually unbranched (or branches 2–3; branched profusely in cultivation), smooth. Roots diffuse or short taproots, largest roots basally 19–63 (average 33) % of greater stem diam. Stems deep-seated with only hemispheric apex protruding above ground level, spheric to cylindric, 1–2.7 × 0.6–1.7 (–2.5) cm; tubercles 2–5 × 2–4 mm; areolar glands absent; parenchyma not mucilaginous; druses present in the stem and tubercle cortex (large lenticular druses absent); pith 1/5–1/3 of lesser stem diam.; medullary vascular system absent. Spines 15–28 per areole, appressed, lightly pigmented, pale tan to pinkish gray, weathering to gray, tips darker on some of largest spines, dark purplish brown to orangebrown, often partly overlain by an ephemeral whitish layer, peglike, not sharply needlelike, proximally compressed laterally; radial spines 13–24 per areole, 3.5–5 × 0.1–0.5 mm, radial/central distinction obscure; subcentral spines usually 1–4 in adaxial parts of areoles; outer central spines (1–) 3 (–4) per areole, in bird’s-foot arrangement at adaxial parts of clusters in adults, straight, inner central spines 0 per areole, longest spines 4–6 × 0.3–0.6 mm. Flowers nearly apical, 13–16 × 15–27 mm; outer tepals fringed; inner tepals 15 or 16 per flower, pale-rose-pink to magenta, shading gradually to paler pink or white basally, sometimes with a darker midstripes distally but lacking well-defined midstripes, proximally whitish to pale yellow-green, 7–12 × 2.5–4 mm; outer filaments whitish to pale yellow-green; anthers yellow to orange-yellow; stigma lobes 4–8, green, 0.5–1.5 mm. Fruits green (sometimes slightly yellow tinted), spheric, obovoid, or obconic, 1.5–6 × 1.5–4 mm, nearly dry; floral remnant persistent but easily broken off. Seeds black, ± obovoid (to weakly pyriform), strophiole squarish, 0.8–1 mm, glossy, deeply pitted. 2n = 22.


Phenology: Flowering spring (Mar-)Apr–May(-Jun); fruiting late summer–fall.
Habitat: Grasslands, closely associated with mats of Selaginella arizonica, novaculite ridges
Elevation: 1200-1400 m

Discussion

Of conservation concern.

Coryphantha minima is a dwarf cactus known only from the vicinity of Marathon, Texas, where it occurs among Selaginella in crevices of Caballos novaculite ledges. The characteristic spines appear blunt—almost club-shaped—and lie flat against the stem, making it one of the safest coryphanthas to handle. The tiny stems, large flowers, and unusual spines make this plant attractive to cactus fanciers. Its population, however, is extremely restricted.

Coryphantha minima is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

None.

Lower Taxa

None.
... more about "Coryphantha minima"
yellow +  and orange-yellow +
protruding +
cushionlike +
circular to linear +
deciduous +  and persistent +
connected +
hourglass--shaped +
Allan D. Zimmerman +  and Bruce D. Parfitt +
spineless +  and naked +
hardened +
Mammillaria subg. Coryphantha +
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 +
Nellie’s pincushion cactus +
with mucilage +  and mucilaginous +
1200-1400 m +
not separating +
1.3 cm13 mm <br />0.013 m <br /> (1.6 cm16 mm <br />0.016 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 />) +
15mm;27mm +
indehiscent +
persistent +, long +  and deciduous +
1.5mm;6mm +
obconic +, obovoid +  and spheric +
fleshy +  and juicy +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Grasslands, closely associated with mats of Selaginella arizonica, novaculite ridges +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
ephemeral +
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 +
4mm +  and 6mm +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
fringed +  and toothed +
small +
whitish +  and pale yellow-green +
not mucilaginous +
deciduous +  and persistent +
Flowering spring (Mar-)Apr–May(-Jun) +  and fruiting late summer–fall. +
mucilaginous +
1/5 +  and 1/3 +
ridgelike +  and nipple--shaped +
Amer. Bot. (Binghamton) +
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 />) +
glossy +  and shiny +
obovoid +
Illustrated +, Endemic +  and Conservation concern +
adventitious +
gray +, pale tan +  and pinkish gray +
weathering +
curved +  and straight +
deciduous +  and persistent +
3.5mm +  and 5mm +
13 (?) +  and 24 (?) +
annulate-ridged +, hairlike +, daggerlike +, subulate +  and acicular +
hard +  and rigid +
differentiated +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
decurrent +
unsegmented +
1.7 cm17 mm <br />0.017 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
1cm;2.7cm +
deep-seated +
tuberculate +
spheric +  and cylindric +
succulent +
0.6cm;1.7cm +
protruding +  and flat +
large +  and small +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
tuberculate +
Coryphantha nellieae +, Escobaria minima +, Escobaria nellieae +  and Mammillaria nellieae +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Coryphantha minima +
Coryphantha +
species +
dull +  and glossy +
pitted +  and raised-reticulate +
needlelike +  and peglike +
brown +  and orangebrown +
compressed +
2mm +  and 5mm +
conic +  and hemispheric or cylindric +
2mm +  and 4mm +
epiphytic;epiphytic;epiphytic +