162 



CACTACEAE 



12. MAMMILLArIA Haw. Syn. PI. Succ. 177. 1812. 



Small, globose, to short-cylindric plants with watery or milky juice. Tubercles terete, 

 angled, or flattened, in spiral rows, usually woolly but glandless in the axils and tipped 

 by spine-areoles ; spines all alike or (in ours) with central ones differing from the radials, 

 often hooded. Flowers diurnal, axillary to the tubercles, campanulate, small, perianth- 

 segments narrow, spreading. Stamens numerous, borne in lower part of the tube, in- 

 cluded. Style equaling stamens. Fruit clavate, naked, scarlet. Seeds brown or (in ours) 

 black, small, shining ; embryo curved. [From the Latin word mammilla, meaning breast, 

 nipple, in reference to the shape of the tubercles.] 



A genus of over ISO species of the southwestern United States and Mexico. Two species occur in the West 

 Indies. Type species, Mammillaria simplex Haw. based on Cactus mammillaris L. 



Outer perianth-segments not ciliate, yellowish; areoles densely woolly when young. 

 Outer perianth-segments ciliate, white tinged with rose or purple; areoles naked. 



1. M. dioica. 



2. M. microcarpa. 



1, Mammillaria dioica K. Brandg. Strawberry Cactus or Pitayita. Fig. 3341. 



Mammillaria dioica K. Brandg. Erythea 5: IIS. 1897. 

 Mammillaria Fordii Orcutt, West Amer. Sci. 13:49. 1902. 

 Neomammillaria dioica Britt. & Rose, Cactaceae 4: 158. 1923. 

 Mammillaria incerta Parish in Jepson, Fl. Calif. 2: 549. 1936. 



Solitary or cespitose, plant-body cylindric, 4-25 {ZZ) cm. tall. Axils of tubercles woolly 

 and more or less short-setose; radial spines 10-20, white, or in some the tips rose-colored, 

 purplish, brown or black, 5-8 mm. long, spreading ; central spines 1^, brown, the lower one 

 stouter and hooked ; flowers yellowish white with a pink or purplish midrib, 10-20 mm. long, 

 incompletely dioecious; inner perianth-segments usually notched at the apex; styles white or 

 greenish ; stigma-lobes yellowish to green ; fruit scarlet, ovoid to clavate, 10-25 mm. long ; seeds 

 black, shining, minutely pitted. 



Grassy hillsides and gravelly slopes, Lower and Upper Sonoran Zones; San Diego County, California, 

 southward along the western side of the mountains to Magdalena Bay, Lower California. Feb.-April. 



2. Mammillaria microcarpa Engelm. Pincushion Cactus. Fig. 3342. 



Mammillaria microcarpa Engelm. in Emory, Notes Mil. Rec. 157. 1848. 



Mammillaria Grahamii Engelm. Proc. Amer. Acad. 3: 262. 1856. 



Cactus Grahamii Kuntze, Rev. Gen. PI. 1:260. 1891. 



Mamtnillaiia Grahamii var. arisontca Quehl, Monatss. Kakteenk. 6: 44. 1896. 



Coryphantha Grahamii Rydb. Fl. Rocky Mts. 581. 1917. 



Neomammillaria microcarpa Britt. & Rose, Cactaceae 4: 155. 1923. 



Cespitose or simple plant 4-8 cm. high, with small tubercles becoming corky in age. Axils 

 of tubercles naked; radial spines 15-30, spreading, white or with dark tips, 6-10 mm. long, 

 usually nearly hiding the flesh of the plant ; central spines 1-3, dark brown to purplish black, 

 if more than one, the lower stouter and hooked, 12-18 mm. long; flowers near the top of the 

 plant, 2-2 . 5 cm. long, broadly f unnelf orm ; outer perianth-segrnents ovate, obtuse ; inner perianth- 

 segments obovate, acuminate, with purplish midribs and whitish margins ; style purple ; stigma- 

 lobes green; fruit clavate, scarlet, 2-2.5 cm. long; seeds black, shining, globose, about 1 mm. in 

 diameter. 



Sandy plains, gravelly slopes and rocky ridges, Lower Sonoran Zone; Santa Rosa Mountains, Colorado 

 Desert, California, to southern Utah, southwestern Texas and the desert areas of central Lower California, 

 Sonora and Chihuahua. Feb. -May. 



^M?i;i'-y^ 







3341 

 3341. Mammillaria dioica 



3342 

 3342. Mammillaria microcarpa 



