1006 CONTRIBUTIONS FEOM THE NATIONAL HERBARIUM. 



118. Neomammillaria microcarpa (Engelm.) Britt. & Rose, Cactaceae 4: 155. 

 1923. 



ilammillaria microcarpa Engelm. in Emory, Mil. Reconn. 157. 1848. 



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



Chihuahua and Sonora. Texas. 



Globose to cylindric, simple or branched either at base or near the middle, 

 often cespitose, sometimes 8 cm. high ; tubercles small, corky when old ; axils 

 of tubercles naked ; radial spines 15 to 30, spreading, white, sometimes with 

 dark tips, slender, rigid, glabrous, 6 to 12 mm. long; central spines 1 to 3, 

 dark, when more than one the lower stouter, often 18 ram. long, hooked ; 

 flowers from near the top of the plant, 2 to 2.5 cm. long, broadly funnel- 

 shaped ; outer perianth segments ovate, obtuse, short-ciliate, the inner pui'plish, 

 sometimes with whitish margins, obovate, acuminate; fruit clavate, 2 to 2.5 

 cm. long, scarlet ; seeds black, shining, pitted. 



Cactus esclianzieri Coulter (Contr. U. S. Nat. Herb. 3: 104. 1894), described 

 from San Luis Potosi, is probably closely related to this species. 



119. Neomammillaria sheldonii Britt. & Rose, Cactaceae 4: 156. 1923. 

 Sonora, the type from Hevmosillo. 



Stems slender-cylindric, about 8 cm. high ; axils of tubercles without setae ; 

 radial spines 12 to 15, pale with dark tips, the 3 or 4 upper ones darker, a 

 little stouter and 1 or 2 of them subcentral, the true central erect or porrect 

 with an upturned hook at the end ; outer perianth segments ciliate, the inner 

 about 10, broad, acute, light purple with very pale margins. 



120. Neomammillaria armillata (K. Brandeg.) Britt. & Rose, Cactaceae 4: 

 157. 1923. 



Mammillaria armillata K. Brandeg. Zoe 5: 7. 1900. 



Southern Baja California ; type from San Jos6 del Cabo. 



In clusters of 3 to 12, cylindric, sometimes 30 cm. high ; tubercles bluish 

 green, somewhat angled ; axils setose and slightly woolly ; radial spines 9 to 15, 

 7 to 12 mm. long, yellowish ; central spines 1 to 4 but usually 2, brownish, the 

 lowest one hooked and a little longer than the others ; flowers 10 to 12 mm. long, 

 greenish to flesh-colored ; fruit red, clavate, 15 to 30 mm. long ; seeds black, 

 punctate. 



121. Neomammillaria fraileana Britt. & Rose, Cactaceae 4: 157. 1923. 

 Islands of Baja California ; type from Pichilinque Island. 



Stems elongate, cylindric, 1 to 1.5 era. long; axils cf tubercles naked or 

 containing at most a single bristle; central spines dark brown, one of them 

 strongly hooked ; flowers rather large, pinkish ; inner perianth segments acumi- 

 nate, 2 to 2.5 cm. long, often lacerate toward the tip. 



122. Neomammillaria swinglei Britt. & Rose, Cactaceae 4: 158. 1923. 

 Sonora ; type from Guaymas. 



Stems cylindric, 10 to 20 cm. long, 3 to 5 cm. in diameter ; axils of tubercles 

 more or less setose; radial spines rather stout for this group, spreading, dull 

 white with dark tips ; central spines 4, ascending, dark brown or black, the 

 lowest one elongate (1 to 1.5 cm.), hooked at apex or sometimes sti'aight; outer 

 perianth segments greenish or sometimes pinkish, the margins somewhat 

 scarious ; inner perianth segments narrowly oblong, nearly white, with a brown 

 stripe down the center ; fruit red, clavate, 18 mm. long ; seeds 1 mm. in diam- 

 eter, black. 



