168 THE CACTACEAE. 
MAMMILLARIA LORICATA Martius in Pfeiffer, Enum. Cact. 13. 1837. 
Echinocactus loricatus Poselger, Allg. Gartenz. 21: 107. 1853. 
Coryphantha loricata Lemaire, Cactées 35. 1868. 
Cactus loricatus Kuntze, Rev. Gen. Pl. 1: 260. 1891. 
Solitary, simple, globose, 4 to 5 cm. in diameter, glaucous-green ; tubercles short-ovate, 4-angled 
at base; radial spines 12, spreading, rigid, yellow, 6 to 8 mm. long; central spines 2, stouter than 
the radials, 8 to 10 mm. long, black at tip, the upper one straight, the lower one curved; flowers and 
fruit not described. 
This plant is recorded as of Mexican origin, but we have found no description of it 
subsequent to the original and it may never be identified. Forster referred it to Mammil- 
laria polythele, but Schumann did not know it. 
Mammillaria heteracantha was referred here as a synonym by Pfeiffer (Enum. Cact. 
13. 1837). This plant was mentioned by Martius (Verz. Konig. Bot. Gard. Miinchen 
127. 1829), but so far as we can learn was never described. 
MAMMILLARIA MONOCENTRA Jacobi, Allg. Gartenz. 24: 90. 1856. 
Depressed-globose, up to 12 cm. high, about 8 cm. in diameter, umbilicate at apex; tubercles 
milky, somewhat rhomboid at base, a little flattened, not setose in their axils; radial spines 6, 
white with black tips, a little spreading; central spine solitary, stouter and longer than the radials, 
about 2.5 cm. long; flowers rather large, rose-colored; style rose-colored; stigma-lobes 6, reddish 
yellow. 
Jacobi referred this plant, presumably of Mexican origin, to the group Angulosae- 
tetragonae of Salm-Dyck. 
Schumann placed it among his list of little-known species; we know it from descrip- 
tion only. 
MAMMILLARIA NERVOSA CRISTATA Journ. Hort. Home Farm. 111. 60: (?) 7. 1910. 
We know this plant only from a brief description and an illustration on pages 7 and 
8 of the journal here cited: 
“ yp es . . . . 7 
Mammillaria nervosus cristatus* grows in convoluted sinuous masses like a great brain-mass. 
The growths are covered with spiny mamillae (whence the name of the genus) and are of a dull 
olive-brownish hue. It, too, is Mexican.” 
We are not able to place this plant; it resembles the cristate form sometimes assumed 
by Pediocactus simpsonit and also resembles Mammillaria bicolor as shown by the illustra- 
tion under M. daedalea. 
Illustration: Journ. Hort. Home Farth. m1. 60: 8 (or 7). 
MAMMILLARIA NICHOLSONI Journ. Hort. Home Farm. m1. 60: 7. I9I0. 
_ We know this species only from the illustration referred to below and the following 
brief note taken from the place of publication: 
“M ammillaria nicholsoni resembles several of the Echinocactuses in external form. It was 
named we believe in honor of the late Mr. George Nicholson and came to Kew from the Swanley 
Collection. All our illustrations were secured at Kew where the collection is well cultivated. M. 
nicholsoni forms spherical masses with the typical protuberances or tubercles, these being tipped 
with sharp spines.”’ 
It is doubtless of Mexican origin. 
Illustration: Journ. Hort. Home Farm. mu. 60: 9. 
MAMMILLARIA NUDA De Candolle, Prodr. 3: 460. 1828. 
This is based on Cactus nudus (Mocifio and Sessé, Pl. Mex. Sc. ined.), but has never been 
subsequently identified. It was also taken up by Otto Kuntze as Cactus nudus (Rev. Gen. 
* This is the original spelling. 
