Mammillaria pottsii

Scheer ex Salm-Dyck

Cact. Hort. Dyck. 1849, 104. 1850.

Common names: Fox-tail cactus rat-tail nipple cactus
Treatment appears in FNA Volume 4. Treatment on page 255. Mentioned on page 249.

Plants usually branched. Roots diffuse; upper portion not enlarged. Stems narrowly cylindric or clavate, 6–15 (–30) × (1.5–) 2–3.5 (–4.5) cm, firm; tubercles 3–5 × 3–5 mm; axils with abundant, persistent, white wool, longest in flowering zone (where exceeding tubercle tips); cortex and pith not mucilaginous; latex absent. Spines (33–) 43–60 per areole, white to gray, tan, or pale reddish (central spines with darker, usually chalky blue tips), glabrous; radial spines (27–) 37–49 per areole, white or pale tan, bristlelike, 3–6 × 0.05–0.1 mm, stiff, contrasting sharply with robust central spines; central spines 6–12 per areole, straight or weakly recurving throughout their lengths, not hooked, all ± projecting, abaxial and lateral central spines straighter and shorter, 5–8 mm, adaxial central spines 10–15 mm, all 0.2–0.3 mm diam. Flowers 0.9–1.5 × 0.6–1.3 cm; outermost tepal margins toothed; inner tepals maroon-red to rusty red or reddish purple, with paler margins, 4 × 1.5 mm; stigma lobes dull pinkish white to reddish purple or orange-yellow, 1 mm. Fruits bright red, cylindric-clavate, 15–20 mm, juicy only in fruit walls; floral remnant persistent. Seeds light to dark-brown, 1–1.2 mm, pitted; testa hard; anticlinal cell-walls deeply sinuate; interstices narrower than pit diameters; pits irregularly bowl-shaped. 2n = 22.


Phenology: Flowering (Feb–Mar, rarely later); fruiting Apr.
Habitat: Chihuahuan desert scrub with Agave lechuguilla and Larrea, gravelly flats, rocky slopes, on limestone or additional substrates
Elevation: 700-1300[-2100] m

Distribution

V4 467-distribution-map.gif

Tex., Mexico (Chihuahua), Mexico (Coahuila), Mexico (Durango), Mexico (Nuevo León), Mexico (Zacatecas)

Discussion

Mammillaria pottsii superficially resembles Coryphantha subgen. Escobaria: the erect cylindric stems are totally concealed by short, pale gray or ashy white spines. In M. pottsii, the ring of reproductive structures (flowers or fruits) encircles the stem two centimeters or more below the stem apex, unlike the apical flowers and fruits of most coryphanthas.

Selected References

None.

Lower Taxa

None.
... more about "Mammillaria pottsii"
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
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 +
Scheer ex Salm-Dyck +
hardened +
triangular +
projecting +  and recurving +
proliferating +
flattened +  and cylindric +
Fox-tail cactus +  and rat-tail nipple cactus +
not mucilaginous +
Tex. +, Mexico (Chihuahua) +, Mexico (Coahuila) +, Mexico (Durango) +, Mexico (Nuevo León) +  and Mexico (Zacatecas) +
700-1300[-2100] 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 /> (7.5 cm75 mm <br />0.075 m <br />) +
unconnected +
0.9 cm9 mm <br />0.009 m <br /> (1.5 cm15 mm <br />0.015 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 />) +
0.6cm;1.3cm +
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 />) +
indehiscent +
persistent +, long +  and deciduous +
5mm;30mm +
cylindric-clavate +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
Chihuahuan desert scrub with Agave lechuguilla and Larrea, gravelly flats, rocky slopes, on limestone or additional substrates +
4 cm40 mm <br />0.04 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 +
deciduous +  and persistent +
Flowering (Feb–Mar, rarely later) +  and fruiting Apr. +
bowl--shaped +
not mucilaginous +
ridgelike +  and nipple--shaped +
Cact. Hort. Dyck. +
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 />) +
pale tan +, white +  and gray tan or pale reddish +
straight +  and curved +
deciduous +  and persistent +
3mm +  and 6mm +
37 (?) +  and 49 (?) +
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 +
0.005 cm0.05 mm <br />5.0e-5 m <br /> (0.01 cm0.1 mm <br />1.0e-4 m <br />) +
decurrent +
unsegmented +
3.5 cm35 mm <br />0.035 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
purplish +, green +  and gray-green +
6cm;15cm +
clavate +  and cylindric +
2cm;3.5cm +
pinkish white +  and reddish purple or orange-yellow +
tuberculate +
Chilita +, Cochemiea +, Dolichothele +, Ebnerella +, Leptocladodia +, Neomammillaria +  and Phellosperma +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Mammillaria pottsii +
Mammillaria +
species +
flat +  and concave +
dull +  and glossy +
not confluent +
3mm +  and 5mm +
cylindric +, conic +  and pyramidal +
3mm +  and 5mm +
not enlarged +
straight +
sinuate +
epiphytic;epiphytic;epiphytic +
barrel-shaped +  and spheric +
persistent +
longest +
persistent +
longest +