STANDLEY TEEES AND SHRUBS OF MEXICO. 975 



Plants 1 to 3 cm. in diameter, fibrous-rooted, entirely hidden by the large 

 overlapping spine clusters ; areoles narrow and long ; spines 20 to 40, all 

 radial, 1.5 to 2 mm. long, white, appressed ; flowers small, lateral, yellow, 

 borne in the axils of old tubercles ; fruit small, naked, oblong ; seeds 1 mm. 

 long, black, smooth. 



50. NEOMAMMILLABIA Britt. & Rose, Cactaceae 4: 65. 1923, 



Plants globose, depressed-globose, or short-cylindric, occasionally much 

 elongate, some with milky, others with watery juice; tubercles arranged in 

 more or less spiraled rows, never on vertical ribs, terete, angled, or some- 

 times flattened, never grooved on the upper surface, usually bearing wool 

 or hairs and sometimes bristles but without glands in their axils and 

 crowned by the spine areoles; spines in clusters on the top of the tubercle, 

 sometimes all alike, sometimes with central ones very different from the 

 radial, all straight or sometimes one or more of the central spines hooked ; 

 flowers, so far as known, diurnal, from axils of the old tubercles, much 

 alike as to size and shape, more or less campanulate, comparatively small 

 variously colored, commonly red, yellowish, or white to pinkish ; perianth 

 segments rather narrow, spreading; stamens numerous, borne on the base 

 of the perianth tube, short, included ; style about the length of the stamens ; 

 stigma lobes linear ; fruit usually clavate, rarely if ever globose, usually 

 ripening rapidly, naked, scarlet; seeds brown in some species, black in 

 others. 



Besides the species here listed about 20 others are found in the south- 

 western United States, West Indies, Central America, and Venezuela. 



The names " biznaguita," " huevos de coyote," and "chilitos" (fruits) are 

 reported from Mexico for species of uncertain determination. According to 

 Hernandez, the milky sap of some species was employed to remove warts. 

 The Tewa Indians of New Mexico are reported to eat the plants raw. 



A. Plants with none of the spines hooked. 

 B. Seeds brown. 



C. Tubercles giving off milk freely wlien cut. 

 D. Axils of tubercles without bristles. 

 E. Tubercles more or less elongate. 

 Tubercles terete throughout. 

 Centi'al spines 1 or 2. 



Central spines about as long as the radials 1, N". gaumeri. 



Central spines much longer than the radials 2. N. petrophila. 



Central spines 4 to 7. 



Outer perianth segments entii-e ; central spines long and 



slender 3. N. arida. 



Outer perianth segments erose ; central spines not elongate, 



stouter 4, N. brandegeei. 



Tubercles more or less angled. 



Tubercles nearly terete toward apex. 



Outer perianth segments and scales more or less fimbriate. 



5. N. g'ummifera. 

 Outer perianth segments and scales entire. 



Radial spines white ; flowers pinkish 6, N. heyderi. 



Radial spines brownish ; flowers white to cream-colored. 



7. N. hemisphaerica. 



