Mammillaria macdougalii

Rose in L. H. Bailey

in L. H. Bailey, Stand. Cycl. Hort. 4: 1982. 1916.

Common names: Cream cactus
Synonyms: Mammillaria gummifera var. macdougalii (Rose) L. D. Benson Mammillaria heyderi var. macdougalii (Rose) L. D. Benson
Treatment appears in FNA Volume 4. Treatment on page 257. Mentioned on page 249, 250.

Plants unbranched, deeply seated in substrate. Roots short, obconic taproots; secondary-roots diffuse. Stems usually flat-topped (in old age or under dense brush hemispheric), 4–20 × 9-25 (–30) cm, firm; tubercles 10–17 × 6–8.5 mm; axils woolly, wool 5–8 mm, bristles absent; cortex and pith not mucilaginous; latex sticky white, abundant in healthy tissue throughout cortex of stem, tubercles, and sometimes flower receptacles. Spines 11–14 (–16) per areole, white to straw yellow, glabrous; radial spines 10–12 per areole, whitish to pale yellowish tan, needlelike, 20 mm, stiff; central spines 1–2 (–4) per areole, ± porrect or 1 ascending and 1 descending, straight or slightly curved, 10 mm; subcentral spines 0. Flowers 3–4 × 2.5–3.5 cm; outermost tepal margins densely minutely fimbriate (at 10×); inner tepals greenish white to greenish yellow, 14–17 (–25) × 2–3 mm; stigma lobes yellow-green to pale green, 2–3 mm. Fruits whitish green proximally, pale green distally with pale rose-purple on sunlit portions, obovoid to clavate, 15–26 × 7.5–15 mm, juicy only in fruit walls; floral remnant persistent. Seeds reddish-brown or orange, 1.1–1.3 × 0.9 × 0.8 mm, pitted; testa intermediate, anticlinal cell-walls undulate, interstices much narrower than pit diam., pits deeply concave, elongate. 2n = 22.


Phenology: Flowering Mar–May; fruiting Oct–Mar.
Habitat: Rocky slopes and ridges, ecotone between Sonoran desert scrub and chaparral, oak woodlands, grasslands
Elevation: 1100-1800 m

Discussion

Mammillaria macdougalii is the characteristic flat-topped mammillaria of the mountains near Tucson and Nogales, Arizona. Records from farther east are all (insofar as can be determined) misidentifications of M. heyderi var. bullingtoniana.

Selected References

None.

Lower Taxa

None.
... more about "Mammillaria macdougalii"
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 +
Rose in L. H. Bailey +
hardened +
triangular +
curved +  and straight +
descending +, ascending +  and porrect +
terete +  and hooked +
10 cm100 mm <br />0.1 m <br /> (?) +
proliferating +
flattened +  and cylindric +
Cream cactus +
not mucilaginous +
Ariz. +  and Mexico (Sonora) +
1100-1800 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 +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 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 />) +
2.5cm;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 />) +
pale rose-purple;pale green;whitish green +
indehiscent +
persistent +, long +  and deciduous +
15mm;26mm +
obovoid +  and clavate +
0.75 cm7.5 mm <br />0.0075 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Rocky slopes and ridges, ecotone between Sonoran desert scrub and chaparral, oak woodlands, grasslands +
1.7 cm17 mm <br />0.017 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
1.4 cm14 mm <br />0.014 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
much narrower +
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 Mar–May +  and fruiting Oct–Mar. +
concave +
elongate +
not mucilaginous +
ridgelike +  and nipple--shaped +
in L. H. Bailey, Stand. Cycl. Hort. +
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 />) +
0.8 cm8 mm <br />0.008 m <br /> (?) +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
obovoid;pyriform;obovoid;pyriform;lenticular-reniform;comma--shaped;spheric +
0.9 cm9 mm <br />0.009 m <br /> (?) +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
tan +, whitish +  and pale yellowish +
straight +  and curved +
deciduous +  and persistent +
10 (?) +  and 12 (?) +
annulate-ridged +, hairlike +, daggerlike +, subulate +  and acicular +
20 cm200 mm <br />0.2 m <br /> (?) +
hard +  and rigid +
decurrent +
unsegmented +
25 cm250 mm <br />0.25 m <br /> (30 cm300 mm <br />0.3 m <br />) +
purplish +, green +  and gray-green +
4cm;20cm +
flat-topped +
9cm;25cm +
yellow-green +  and pale green +
tuberculate +
Mammillaria gummifera var. macdougalii +  and Mammillaria heyderi var. macdougalii +
adventitious +
epipetric +  and epiphytic +
Mammillaria macdougalii +
Mammillaria +
species +
flat +  and concave +
dull +  and glossy +
intermediate +
not confluent +
10mm +  and 17mm +
cylindric +, conic +  and pyramidal +
6mm +  and 8.5mm +
straight +
sinuate +
epiphytic;epiphytic;epiphytic +
barrel-shaped +  and spheric +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +