Mammillaria thornberi

Orcutt

W. Amer. Sci. 12: 161. 1902.

Common names: Thornber ’s nipple cactus
Treatment appears in FNA Volume 4. Treatment on page 253. Mentioned on page 247, 248.

Plants branching prolifically from base, every branch with independent root system, connections to rest of clone ephemeral, resulting in dense clumps of independently rooted stems. Roots diffuse, upper portion not enlarged. Stems slender cylindric, 4.5–10 (–30) × 2–3.5 cm, tapered at base, firm; tubercles 5–9 × 5–9 mm; axils appearing naked; cortex and pith not mucilaginous; latex absent. Spines 14–22 (–23) per areole, whitish to yellowish near base, pale reddish-brown to nearly black toward tips, glabrous; radial spines 13–21 per areole, whitish, with reduced dark tips relative to central spines, bristlelike, 5–9 × 0.16 mm, stiff; central spines 1 (–3) per areole, porrect, hooked, (7–) 9–18 × 0.16–0.45 mm; subcentral spines 0 (–3) per areole, adaxial to central spines, ± transitional to radial spines. Flowers 1.5–3 × 1.2–2.5 cm; outermost tepal margins densely short fringed; inner tepals white or pinkish with bright-rose-pink midstripes, 14–19 × 5–7 mm; stigma lobes magenta, 3–6 mm. Fruits bright red, obovoid to nearly clavate, 7–15 × 4–7 mm, juicy only in fruit walls; floral remnant persistent. Seeds black, 0.9–1.1 × 0.8–1.1 × 0.7 mm, pitted; testa hard, brittle; anticlinal cell-walls straight (not undulate); interstices conspicuously wider than pit diameters; pits bowl-shaped. 2n = 22.


Phenology: Flowering Apr–May, Jul–Aug; fruiting Oct–Nov, Feb–Mar.
Habitat: Sonoran desert scrub, valley floors, under shrubs, silty or sandy soils
Elevation: 400-600 m

Discussion

The epithet fasciculata was long misapplied to Mammillaria thornberi; it correctly pertains to Echinocereus fasciculatus (Engelmann) L. D. Benson.

Mammillaria thornberi is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

None.

Lower Taxa

None.
... more about "Mammillaria thornberi"
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 +
Orcutt +
hardened +
triangular +
0.7 cm7 mm <br />0.007 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
curved +  and straight +
9mm +  and 18mm +
0.016 cm0.16 mm <br />1.6e-4 m <br /> (0.045 cm0.45 mm <br />4.5e-4 m <br />) +
proliferating +
flattened +  and cylindric +
Thornber ’s nipple cactus +
not mucilaginous +
Ariz. +  and Mexico (Sonora) +
400-600 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 +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 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 />) +
1.2cm;2.5cm +
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 />) +
indehiscent +
persistent +, long +  and deciduous +
7mm;15mm +
obovoid +  and nearly clavate +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Sonoran desert scrub, valley floors, under shrubs, silty or sandy soils +
1.4 cm14 mm <br />0.014 m <br /> (1.9 cm19 mm <br />0.019 m <br />) +
conspicuously wider +
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 +
bright-rose-pink +
deciduous +  and persistent +
Flowering Apr–May, Jul–Aug +  and fruiting Oct–Nov, Feb–Mar. +
bowl--shaped +
not mucilaginous +
ridgelike +  and nipple--shaped +
W. Amer. Sci. +
bristly +  and woolly +
ephemeral +
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 />) +
0.7 cm7 mm <br />0.007 m <br /> (?) +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
obovoid;pyriform;obovoid;pyriform;lenticular-reniform;comma--shaped;spheric +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
whitish +, pale reddish-brown +  and nearly black +
straight +  and curved +
deciduous +  and persistent +
5mm +  and 9mm +
13 (?) +  and 21 (?) +
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 +
0.16 cm1.6 mm <br />0.0016 m <br /> (?) +
decurrent +
12 cm120 mm <br />0.12 m <br /> (20 cm200 mm <br />0.2 m <br />) +
purplish +, green +  and gray-green +
4.5cm;10cm +
tapered +  and cylindric +
slender +
2cm;3.5cm +
tuberculate +
Chilita +, Cochemiea +, Dolichothele +, Ebnerella +, Leptocladodia +, Neomammillaria +  and Phellosperma +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Mammillaria thornberi +
Mammillaria +
species +
flat +  and concave +
dull +  and glossy +
reduced +
not confluent +
5mm +  and 9mm +
cylindric +, conic +  and pyramidal +
5mm +  and 9mm +
not enlarged +
straight +
sinuate +
epiphytic;epiphytic;epiphytic +
barrel-shaped +  and spheric +