1000 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



IMammillaria suhechmata Salm-Dyck, Cact. Hort. Dyck. 1849. 101. 1850. 



Mammillaria rufocrocea Salm-Dyck, Cact. Hort. Dyck. 1849. 102. 1850. 



Eastern Mexico. 



Densely cespitose, forming small clumps, erect, ascending, or prostrate, 3 

 to 10 cm. long, 1 to 1.5 cm. in diameter, almost covered by a mass of inter- 

 locking spines ; tubercles arranged in few rows, usually in spirals, short, their 

 axils naked ; spines usually all radial but sometimes with 1 porrect central 

 spine, yellow or with brown tips, more or less recurved, 8 to 12 mm. long; 

 spine areoles pube.scent when young; flowers at the upper part of the plant 

 but from the axils of old tubercles, white or nearly so, rather short and broad, 

 6 to 7 mm. long; perianth segments about 12, rather broad, obtuse or some- 

 times apiculate. 



88. ITeomammillaria echinaria (DC.) Britt. & Rose, Cactaceae 4: 136. 1923. 

 Mammillaria echinaria DC. M§m. Mus. Hist. Nat. 17: 110. 1828. 

 Mammillaria ecJiinnta DC. M6m. Cact. 3. 1834. 



Mammillaria gracilis Pfeiff. Allg. Gartenz.'6: 275. 1838. 



Hidalgo. 



Plants cespitose, often forming large clumps, ascending or spreading, 1 to 

 1.5 cm. in diameter ; tubercles short, terete, their axils naked ; spines pale yel- 

 low to glossy white; radial spines about 15, spreading; central spines one, 

 straight, acicular, about 1 cm. long ; flowers and fruit not known. 



89. Neomammillaria pottsii (Scheer) Britt. & Rose, Cactaceae 4: 136. 1923. 

 Mammillaria pottsii Scheer; Salm-Dyck, Cact. Hort. Dyck. 1849. 104. 1850. 

 Mammillaria leona Poselger, Allg. Gartenz. 21: 94. 1853. 



Nuevo Le6n, Coahuila, Chihuahua, and Zacatecas. Texas. 



More or less cespitose. the individual plants cylindric, 12 cm. long or more; 

 tubercles almost hidden by the spines ; radial spines about 30, white, weak, 

 short ; central spines 6 to 12, much stouter and longer, more or less ascending, 

 grayish with brown tips ; axils of tubercles woolly ; flowers borne in a circle 

 about 2 cm. below the top of the plant, about 1 cm. long ; inner perianth seg- 

 ments light purple, somewhat spreading at tip, acute; fruit red, clavate; 

 seeds blackish brown, the surface deeply pitted. 



90. Neomanim.illaria mazatlanensis (Schum.) Britt. & Rose, Cactaceae 4: 

 138. 1923. 



Mammillaria mazatlanensis Schum. Monatsschr. Kakteenk. 11: 154. 1901. 



Mammillaria Uttoralis K. Brandeg. Kew Bull. Misc. Inf. 1908: App. 91. 1908. 



On hills near the sea, about Mazathin, Sinaloa. 



Plants cespitose, often forming broad clumps with many oblong heads, 4 to 

 10 cm. long, about 2 cm. in diameter ; tul)ercles terete, 3 to 4 mm. long, their 

 axils naked ; radial spines 12 to 15, setaceous, spreading, white ; central spines 

 4 to 6, stouter than the radials, reddish, ascending, 8 to 10 mm. long ; flowers 

 from the axils of the old tubercles but toward the top of the plant, 3 cm. 

 long or more, red ; perianth segments oblong, spreading. 



91. Neomammillaria sphacelata (Mart.) Britt. & Rose, Cactaceae 4: 138. 

 1923. 



Mammillaria sphacelata Mart. Nov. Act. Nat. Cur. 1.6: 339. 1832. 



Puebla and Oaxaca. 



Usually densely cespitose, often grayish, forming clumps 30 to 40 cm. in 

 diameter, the individual plants cylindric, more or less elongate, often 10 to 

 20 cm. high; radial spines 14 to 20, usually white with black tips; central 

 spines 3 or 4, usually black or reddish throughout, sometimes becoming white 

 in age; axils of tubercles often bearing tufts of short hairs and occasionally 



