NEOMAMMILLARIA. 99 
Mammillaria nivea cristata Salm-Dyck (Walpers, Repert. Bot. 2: 270. 1843) is only a 
name. M. nivea wendlei Pfeiffer (Labouret, Monogr. Cact. 57- 1853) was given as a 
synonym of M. bicolor. 
To this relationship we would refer the plant which has long been known in collections 
under the name of Mammillaria potosina* and M. potosina var. longispina. It resembles 
M. celsiana in the spines, but the tubercles are milky and the stem is more elongated. 
We have seen the following illustration: Méllers Deutsche Gart. Zeit. 25: 475. f. 8, No. 9, 
as M. potosina. 
De Candolle (Prodr. 3: 459. 1828) referred here Cactus columnaris Mocifio and Sessé. 
Fic. 96.—Neomammillaria collinsii. Fic. 97.—Neomammillaria geminispina. 
Illustrations: Wiener Ill. Gart. Zeit. 11: pl. 3, in part, as Mammillaria nobilis; Hort. 
Belge 4: pl. 1, as M. daedalea; Mdllers Deutsche Gart. Zeit. 25: 475. f. 8, No. 4, as M. 
bicolor nobilis; Cact. Journ. 1: pl. for March, as M. nivea cristata; Cact. Journ. 1: pl. for 
March, as M. nivea longispina; Pfeiffer and Otto, Abbild. Beschr. Cact. 1: pl. 3; De Laet, 
Cat. Gén. f. 50, No. 8; Wiener III. Gart. Zeit. 29: f. 22, No. 8; Knippel, Kakteen pl. 19, as 
M. bicolor. 
Plate v, figure 3, shows a flowering plant sent by Carl Ackerman which flowered in the 
New York Botanical Garden, October 9, 1920; plate vit, figure 5, shows a plant which 
flowered in the New York Botanical Garden, November 11, I9II. Figure 97 is from a 
photograph by Emest Braunton showing a plant grown in southern California. 
44. Neomammillaria pyrrhocephala (Scheidweiler). 
Mammillaria pyrrhocephala Scheidweiler, Allg. Gartenz. 9: 42. 1841. 
Mammillaria mallettiana Cels, Shen ar oe 222. 446 
Mammillaria senckei{ Forster, Handb. Cact. 227. 1 . 
Mammillaria pyrrhocephala donkelaert Salm-Dyck, Cact. Hort. Dyck. 1849. 17, 121. 
Cactus pyrrhocephalus Kuntze, Rev. Gen. Pl. 1: 261. 1891. 
. 4s . bglaucous; areoles bearing yel- 
Cylindric; axils lanate and setose; tubercles angled, green or subg ucous; are 
lowish wool; spines all black when young, when. old becoming gray below; radial spines 6, spreading, 
the upper ones a little longer; central spines single, erect; flowers red. 
1850. 
Type locality: Real del Monte, Mexico. 
Distribution: Hidalgo and, perhaps, Oaxaca. 
* This name is sometimes credited to Rebut (M@llers Deutsche Gart. Zeit. 25: 47 
it we a fit. «ig. 
t This was originally written M. senkii, although the plant was named for F. Senke of Leipzig 
5. 1910) but if he published 
