1002 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



97. Neomanxmillaria rekoi Britt. & Rose, Cactaceae 4: 141. 1923. 

 Oaxaca. 



Globular to short-cylindric, becoming 10 cm. long, 5 to 6 cm. in diameter, 

 not milky ; tubercles green, terete, 8 to 10 mm. long, not very closely set, 

 each bearing in its axil a tuft of short white wool and 5 to 8 long white 

 bristles ; radial spines spreading, about 20, white, delicately acicular, 4 to 6 

 mm. long ; central spines 4, brown, much stouter than the radials, 10 to 

 15 mm. long, the lower one usually strongly hooked ; flowers from axils of 

 old tubercles, near the top of the plant, 1.5 cm. long, deep purple; inner 

 perianth segments narrowly oblong, apiculate ; fruit clavate, red, 12 mm. 

 long ; seeds minute, brown. 



98. Neomammillaria solisii Britt. & Hose, Cactaceae 4: 142. 1923. 

 Guerrero, the type from Cerro de Buenavista de Cuellar. 



Simple, globose or nearly so, 5 to 7 cm. in diameter, green or becoming pur- 

 plish ; tubercles 8 mm. long, terete, a little narrow toward the tip and thus 

 separated above from the adjoining tubercles, their axils without wool even 

 when young and usually with 1 to many bristles ; radial spines 10 to 20, spread- 

 ing, 6 to 7 mm. long, white, bristle-like ; central spines 3 or 4, a little stouter than 

 the radials, becoming brown, one of them strongly hooked (sometimes 2 cm. 

 long) ; flowers from axils near base of the plant; ovary remaining dormant for 

 a long time (at least a month), then elongating and the fruit maturing quickly, 

 this short-oblong, 10 to 12 mm. long, green ; seeds 1 mm. long, brown, pitted. 



99. Neomammillaria pygmaea Britt. & Rose, Cactaceae 4: 142. 1923. 

 Queretaro ; type from Cadereyta. 



Plant very small, globose to cylindric, 2 to 3 cm. in diameter ; tubercles 

 small, obtuse ; radial spines about 15, white, stiff, hardly puberulent even under 

 a lens; central spines 4, ascending, golden yellow, the lower one hooked, 5 to 

 6 cm. long; flowers about 1 cm. long, the outer segments tinged with red, apic- 

 ulate ; inner perianth segments about 10, cream-colored. 



100. Neomammillaria wildii (Dietr.) Britt. & Rose, Cactaceae 4: 143. 1923. 

 Mammillaria wildii Dietr. AUg. Gartenz. 4: 137. 1836. 



Hidalgo. 



Cylindric to globose, cespitose at base ; axils of tubercles bearing rose-colored 

 hairs and bristles ; tubercles slender, elongate, 8 to 10 mm. long, obtuse, green 

 or somewhat rose-colored at base ; young areoles tomentose ; spines all puberu- 

 lent ; radial spines 8 to 10, 8 mm. long, setiform, white ; central spines 4, yel- 

 low, one of them hooked ; flowers white, 12 mm. in diameter ; inner perianth 

 segments acuminate; fruit clavate, red. 



101. Neomammillaria seideliana (Quehl) Britt. & Rose, Cactaceae 4: 144. 

 1923. 



Mammillaria seideliana Quehl, Monatsschr. Kakteenk. 21: 154. 1911. 



Zacatecas. 



Solitary, globose, becoming cespitose, 3 to 4 cm. in diameter; tubercles 

 purplish, their axils naked; radial spines 20 to 25, white, long and slender, 

 ascending, puberulent ; central spines yellow, 3 or 4, one hooked, puberulent 

 when young ; flowers arising from near the top of the plant, 15 to 18 mm. long, 

 creamy yellow, the outer perianth segments brownish, the inner oblong, 

 acute; fruit persisting in the axils of the tubercles apparently for a number 

 of years ; seeds black. 



