984 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Depressed-globose, 2 to 3 cm. high, 6 to 15 cm. in diameter ; axils of old tuber- 

 cles naked, of young ones densely lanate; tubercles ovoid, somewhat 4-sided; 

 young spine areoles somewhat tomentose ; spines 1 or 2, somewhat angled, elon- 

 gate, the longest 5 cm. long, porrect or more or less reflexed, white or yel- 

 lowish ; flowers dark pink, a little longer than the tubercles ; perianth segments 

 linear, spreading. 



11. Neomammillaria johnstonii Britt. & Rose, Cactaceae 4: 80. 1923. 

 Type from San Carlos Bay, Sonora. 



Plants large for the genus, globular to short-oblong, 1.5 to 20 cm. high, 

 slightly depressed at apex; tubercles 1 to 1.3 cm. long, 4-angled throughout, 

 somewhat bluish, naked in the axils, milky ; spine areoles when young short- 

 floccose, in age glabrate, terete; radial spines 10 to 14, white but with brown 

 tips, somewhat spreading, stiff-acicular ; central spines 2, much longer and 

 stouter than the radials, slightly diverging, bluish brown ; flowers from near 

 the top of the plant but from the axils of old tubercles, carapanulate, 2 cm. 

 long; outer perianth segments ovate-lanceolate, greenish white with a reddish 

 brown midrib ; inner perianth segments narrow, acuminate, white. 



12. Neomammillaria melanocentra (Po.selg.) Britt. & Rose, Cactaceae 4: 81. 

 1923. 



Mammillaria melanocentra Poselg. Allg. Gartenz. 23: 17. 1855. 



Mammillaria erinacea Poselger, Allg. Gartenz. 23: 18. 1855. 



Mammillaria valida Weber, Diet. Hort. Bols SOG. 1898. 



Mexico ; type from Monterrey, Nuevo Leon. 



Short-cylindric, glaucous-green ; tubercles in 8 and 13 spirals, strongly 

 angled ; radial spines 6, stout-subulate, 1.5 to 2 cm. long, brownish ; central 

 spines solitary, black, 2 to 3 cm. long, greatly overtopping the stem ; flowers 

 pinkish red, the segments linear, acute. 



13. Neomammillaria runyonii Britt. & Rose, Cactaceae 4: 81. 1923. 

 Type from El Slirador, near Monterrey, Nuevo Leon. 



Plants deep-seated, depressed; tubercles milky, elongate, 1.5 cm. long, 

 strongly 4-angled, their tips widely separated, the axils long-woolly (never 

 setose), especially when young, sometimes permanently so; young spine areoles 

 long-woolly, in age glabrate; radial spines 6 to 8, slightly ascending, the outer 

 ones stouter and often dark brown, the inner ones about half the length of 

 the outer and nearly white ; central spine solitary, brown to black, erect, 10 

 to 14 mm. long ; flowers about 2 cm. long, purple ; perianth segments oblong ; 

 fruit red, clavate, 12 to IG mm. long ; seeds brown. 



14. Neomammillaria sartorii (Purpus) Britt. & Rose, Cactaceae 4: 82. 1923. 

 Mammillaria sartoi'ii Purpus, Monatssclir. Kakteenk. 21: 50. 1911. 

 Veracruz, the tj'pe from Barranca de Pancaya. 



Globose to short-cylindric, 5 to 13 cm. in diameter, cespitose, very milky. 

 bluish green ; tubercles strongly 4-angled, pointed. 8 to 12 mm. long, their 

 axils without bristles and in time without wool ; spine areoles circular when 

 young, densely white-woolly but in age glabrate : spines 4 to 6, very unequal, 

 5 to 8 mm. long, whitish or sometimes brownish, the central spine solitary ; 

 flowers 1.5 to 2 cm. long, deep carmine ; perianth segments oblong, apiculate, 

 the tip dry, the outer ones ciliate, the inner serrulate ; fruit carmine ; seeds 

 brown. 



15. Neomammillaria seitziana (Mart.) Britt. & Rose, Cactaceae 4: 83. 1923. 

 Mammillaria seitziana Mart.; Pfeiff. Enum. Cact. 18. 3837. 

 Mammillaria foveolata Miihlenpf. Allg. Gartenz. 14: 372. 1846. 

 Hidalgo, the type from Ixmiquilpan. 



