Mammillaria meiacantha

Engelmann

Proc. Amer. Acad. Arts 3: 263. 1856.

Common names: Nipple cactus
Synonyms: Mammillaria gummifera var. meiacantha (Engelmann) L. D. Benson Mammillaria heyderi var. meiacantha (Engelmann) L. D. Benson Mammillaria runyonii (Britton & Rose) Boedeker
Treatment appears in FNA Volume 4. Treatment on page 256. Mentioned on page 249.

Plants unbranched. Roots short, obconic taproots; secondary-roots diffuse. Stems flat-topped (in old age or under dense brush aerial portion of stem hemispheric), 10 × 8–10 (–30) cm, firm; tubercles 8–17 × 4–11 mm; axils bearing (at least seasonally) woolly tufts, wool 3–5 mm, bristles absent; cortex and pith not mucilaginous; latex abundant in healthy tissue throughout cortex of stem, tubercles, and sometimes flower receptacle, sticky, white. Spines (6–) 7–8 (–10) per areole, white, reddish-brown, gray, or yellowish, glabrous; radial spines (5–) 6–7 (–9) per areole, largest spines reddish-brown, gray, or yellowish, tips blackish or dark-brown, needlelike, 6.5–13.5 × 0.3–0.6 mm, stiff; central spines (0–) 1 per areole, usually ascending and inconspicuous against radial spines, sometimes porrect, straight or slightly curved, largest spines (3–) 5–12 × 0.3–0.7 mm; subcentral spines 0. Flowers 2.5–3.5 × 1.9–3.5 (–4.4) cm; outermost tepal margins entire; inner tepals white to pale-pink, often with pink or lavender midstripes, 8–15 mm; stigma lobes light green, 3–5 mm. Fruits purplish-pink, clavate to obovoid, 20–32 mm, juicy only in fruit walls; floral remnant weakly persistent. Seeds reddish-brown, 1.1–1.2 mm; pitted; testa leathery to hard, anticlinal cell-walls strongly undulate, interstices much narrower than pit diam., pits deeply concave, elongate. 2n = 22.


Phenology: Flowering Mar–May(-Jun); fruiting Oct–Mar.
Habitat: Great Plains grasslands, pine-oak woodlands, ecotone between Chihuahuan desert scrub adjacent more mesic habitats
Elevation: 900-2500 m

Discussion

Mammillaria meiacantha is regionally sympatric with both varieties of M. heyderi, without resulting in hybridization. West of the Rio Grande, reports of M. meiacantha probably are misidentifications of M. heyderi var. bullingtoniana. Mammillaria meiacantha has not been documented for Arizona.

Selected References

None.

Lower Taxa

None.
... more about "Mammillaria meiacantha"
cushionlike +
needlelike +  and bristlelike +
circular to linear +
2.5 cm25 mm <br />0.025 m <br /> (3.1 cm31 mm <br />0.031 m <br />) +
deciduous +  and persistent +
0.2 cm2 mm <br />0.002 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
plumose +  and hairlike +
0.001 cm0.01 mm <br />1.0e-5 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Allan D. Zimmerman +  and Bruce D. Parfitt +
Engelmann +
hardened +
triangular +
curved +  and straight +
porrect +  and ascending +
terete +  and hooked +
proliferating +
flattened +  and cylindric +
Nipple cactus +
not mucilaginous +
N.Mex. +, Tex. +  and Mexico +
900-2500 m +
not separating +
4 cm40 mm <br />0.04 m <br /> (5.2 cm52 mm <br />0.052 m <br />) +
3.5 cm35 mm <br />0.035 m <br /> (4.4 cm44 mm <br />0.044 m <br />) +
unconnected +
2.5 cm25 mm <br />0.025 m <br /> (3.5 cm35 mm <br />0.035 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 />) +
1.9cm;3.5cm +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.9 cm9 mm <br />0.009 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
purplish-pink +
indehiscent +
persistent +, long +  and deciduous +
5mm;30mm +
clavate +  and obovoid +
2 cm20 mm <br />0.02 m <br /> (3.2 cm32 mm <br />0.032 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
Great Plains grasslands, pine-oak woodlands, ecotone between Chihuahuan desert scrub adjacent more mesic habitats +
0.4 cm4 mm <br />0.004 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1.5mm;8.5mm +
much narrower +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
yellowish +, gray +  and reddish-brown +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 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 +
lavender +  and pink +
deciduous +  and persistent +
Flowering Mar–May(-Jun) +  and fruiting Oct–Mar. +
concave +
elongate +
not mucilaginous +
ridgelike +  and nipple--shaped +
Proc. Amer. Acad. Arts +
bristly +  and woolly +
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 />) +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
obovoid;pyriform;obovoid;pyriform;lenticular-reniform;comma--shaped;spheric +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
yellowish +, gray +, reddish-brown +  and white +
straight +  and curved +
deciduous +  and persistent +
6 (?) +  and 7 (?) +
annulate-ridged +, hairlike +, daggerlike +, subulate +  and acicular +
0.3 cm3 mm <br />0.003 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
hard +  and rigid +
decurrent +
unsegmented +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
purplish +, green +  and gray-green +
flat-topped +
8cm;10cm +
tuberculate +
Mammillaria gummifera var. meiacantha +, Mammillaria heyderi var. meiacantha +  and Mammillaria runyonii +
adventitious +
epipetric +  and epiphytic +
Mammillaria meiacantha +
Mammillaria +
species +
fringed +  and entire +
flat +  and concave +
dull +  and glossy +
leathery +  and hard +
dark-brown +  and blackish +
6.5mm +  and 13.5mm +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (?) +  and 0.06 cm0.6 mm <br />6.0e-4 m <br /> (?) +
not confluent +
8mm +  and 17mm +
cylindric +, conic +  and pyramidal +
4mm +  and 11mm +
straight +
sinuate +
epiphytic;epiphytic;epiphytic +
barrel-shaped +  and spheric +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +