Mammillaria geminispina Haworth 1824

TWIN-SPINED CACTUS, WHITEY

? Mammillaria elegans A. P. de Candolle 1828

Mammillaria leucocentra Berg 1840, M. geminispina subsp. leuco-

centra (Berg) D. R. Hunt 1997 Mammillaria albata Reppenhagen 1987

Plants forming large clumps that appear white. Stems short cylindrical, light green, to 18 cm (7.1 in) high and 8 cm (3.1 in) in diameter. Tubercles rounded, with latex, axils with white wool and 10-20 long white bristles. Central spines 2-

6, erect, straight to slightly curved, pure white or white with dark tips, to 40 mm (1.6 in) or more long. Radial spines 1620, needle-like, chalky white, interlacing, 5-7 mm (0.2-0.3 in) long. Flowers deep pink to carmine red, with darker mid-veins, to 20 mm (0.8 in) long and in diameter. Fruits carmine red. Seeds brown. Distribution: Hidalgo, Querétaro, and San Luis Potosí, Mexico.

Two subspecies of Mammillaria geminispina are recognized. Subspecies geminispina has 2 central spines that are white with dark tips. Subspecies leucocentra has 5-6 pure white central spines.

Mammillaria gigantea Hildmann ex K. Schumann 1898 Neomammillaria hamiltonhoytea Bravo 1931, Mammillaria hamilton-

hoytea (Bravo) Werdermann ex Backeberg 1931 Mammillaria armatissima R. T. Craig 1945 Mammillaria ocotillensis R. T. Craig 1945 Mammillaria hastifera Krainz & Keller 1946 Mammillaria saint-pieana Backeberg ex Mottram 1980

Plants solitary. Stems depressed globose, blue-green, 9-10 cm (3.5-3.9 in) high, 15-17 cm (5.9-6.7 in) in diameter. Tubercles blunt pyramidal, four-angled, with latex, axils woolly. Central spines 4-6, robust, dark yellow, becoming brownish with age, to 20 mm (0.8 in) long, lowermost one longest. Radial spines as many as 12, needle-like, white, to 3 mm long. Flowers yellowish green, to 15 mm (0.6 in) long and in diameter. Fruits dull pink to greenish. Seeds brown. Distribution: Guanajuato, Durango, San Luis Potosí, and Querétaro, Mexico.

Mammillaria glassii R. Foster 1968 Mammillaria ascensionis Reppenhagen 1979, M. glassii subsp. as-censiowi's (Reppenhagen) D. R. Hunt 1997

Plants forming clusters. Stems globose, becoming cylindrical, 3-10 cm (1.2-3.9 in) high and in diameter. Tubercles

Mammillaria Geminispina
Mammillaria geminispina subsp. geminispina

Mammillaria grahamii 419

cylindrical, without latex, axils with 20-30 white bristles to 25 mm (1 in) long or nearly naked. Central spines 1-8,4-7 mm (to 0.3 in) long, one erect, straight or hooked, others difficult to distinguish from radials. Radial spines 50-60, hairlike, white, interlacing, 10-15 mm (0.4-0.6 in) long. Flowers often not opening completely, light pink, to 14 mm (0.6 in) long, 3-22 mm (to 0.9 in) in diameter. Fruits green, becoming pink, to 20 mm (0.8 in) long. Seeds black. Distribution: Coahuila, Tamaulipas, and Nuevo León, Mexico.

Two subspecies of Mammillaria glassii are recognized. Subspecies glassii has stems rarely exceeding 3 cm (1.2 in) in diameter, tends to have axillary white bristles, and has one central spine, and flowers to 3.5 mm in diameter; it occurs in Coahuila, Tamaulipas, and Nuevo León. Subspecies ascensi-onis has stems to 10 cm (3.9 in) in diameter, areoles with short white wool but few bristles, central spines 5-7 mm (0.2-0.3 in) long, and flowers 18-22 mm (0.7-0.9 in) in diameter; it occurs near Ascension, Nuevo León.

Mammillaria glochidiata Martius 1832 Chilita glochidiata (Martius) Orcutt 1926, Ebnerella glochidiata (Martius) Buxbaum 1951 Mammillaria wildii A. Dietrich 1836, Chilita wildii (A. Dietrich) Orcutt 1926, Ebnerella wildii (A. Dietrich) Buxbaum 1951, M. crinita subsp. wildii (A. Dietrich) D. R. Hunt 1997

Plants irregularly forming clusters. Stems cylindrical, glossy bright green, rounded apically, 2-3.5 cm (0.8-1.4 in) in diameter. Tubercles flabby, widely separated, cylindrical to conical, 12-16 mm (0.5-0.6 in) long, without milky sap, some axils with bristles. Central spines 1-4, needle-like, lower one hooked, dark yellow to reddish brown, 6-12 mm (0.2-0.5 in) long. Radial spines 9-11, threadlike, flexible, smooth, white, horizontal, to 12 mm (0.5 in) long. Flowers bell shaped, white to pink, to 15 mm (0.6 in) long and 12 mm (0.5 in) in diameter. Fruits club shaped, scarlet, to 16 mm (0.6 in) long. Seeds brownish black. Distribution: Hidalgo, Mexico. Mammillaria glochidiata may be only a variant of M. crinita; W. A. and Betty Fitz Maurice (1997b) compare the two.

Mammillaria goodridgei Salm-Dyck 1850 Chilita goodridgei (Salm-Dyck) Orcutt 1926, Ebnerella goodridgei (Salm-Dyck) Buxbaum 1951

Plants occasionally clustering. Taproots deep. Stems globose to short cylindrical, to 8 cm (3.1 in) high, 3-4 cm (1.2-1.6 in) in diameter. Tubercles tapering cylindrical, obtuse, without latex, axils naked. Central spines 3-5, brown, to 6 mm (0.2 in) long, lower one usually hooked. Radial spines 10-13, chalky white with dark tips, straight, spreading, 4-7 mm (to

0.3 in) long. Flowers funnelform, cream colored with purplish pink midveins, to 15 mm (0.6 in) long and in diameter. Fruits club shaped, red, to 25 mm (1 in) long. Seeds black, smooth. Distribution: Cedros and Guadalupe Islands, Baja California, Mexico.

Continue reading here: Mammillaria grahamii Engelmann 1856

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