170 THE CACTACEAE. 
This plant, recorded as of Mexican origin, was at one time offered for sale by A. Blanc 
and Company; we know it only from description and are unable to identify it. 
MAMMMILLARIA SEEMANNII Scheer in Seemann, Bot. Herald 288. 1856. 
Cactus seemannit Kuntze, Rev. Gen. Pl. 1: 261. 1891: 
Hemispheric, stout, 10 cm. in diameter, 7.5 cm. high; tubercles somewhat ovoid, elongated, 
greenish, minutely punctate, their axils soon white-woolly; radial spines 11 to 13, nearly equal, less 
than 6 mm. long; central spines 1, shorter than the radials, subulate, straight, erect, blackish purple, 
becoming white. 
This plant was sent to F. Scheer in 1850, who states that it came from Sonora or 
Durango. It is incompletely described and can not be identified. It may be a species of 
Coryphantha. 
MAMMILLARIA SORORIA Meinshausen, Wochenschr. Gartn. Pflanz. 1: 28. 1858. 
Cactus sororius Kuntze, Rev. Gen. Pl. 1: 261. 1891. 
Depressed-globose, 5 to 6 cm. high, 7.5 to 10 cm. in diameter, milky; tubercles angled, 12 mm. 
long, naked in their axils; radial spines 6, 4 mm. long; central spines 1, erect, stouter than the 
radials, blackish at apex; flowers greenish purple; stigma-lobes 4. 
Recorded as of Mexican origin but otherwise unknown. 
MAMMILLARIA SPINAUREA Salm-Dyck, Allg. Gartenz. 18: 594. 1850. 
Cactus spinaureus Kuntze, Rev. Gen. Pl. 1: 261. 1891. 
Globose or becoming depressed; tubercles light green, somewhat 4-angled, gibbous at base, 
obtuse and oblique at apex, their axils woolly; radial spines about 12, slender, rigid, spreading; 
central spines 5 or 6, twice as long and stouter than the radials, recurved or reflexed, yellow. 
The above was sent by John Potts from Chihuahua in 18 50; Scheer thought that it 
might have been collected in Durango or Sonora. We have not been able to identify it. 
MAMMILLARIA SUAVEOLENS Riimpler in Forster, Handb. Cact. ed. 2. 297. 1885. 
About 4 em. high; radial spines 13 to 15; central spines 4, brown; flowers and fruit unknown. 
The above is unidentifiable from the brief description. It was grown in Germany. 
from Mexican seed. 
MAMMILLARIA TROHARTI Hildmann in Schumann, Gesamtb. Kakteen 586. 1898. 
Simple or proliferous and densely cespitose, globose or somewhat depressed, glaucous-green, 
small (6 cm. in diameter); axils naked; areoles at first woolly, afterwards naked; tubercles very 
small, scarcely angled; radial spines 5, with brown tips; central spines solitary, dark brown, subulate; 
flowers and fruit unknown. 
M. trohartii is of Mexican origin. 
MAMMILLARIA UNISETA Quehl, Monatsschr. Kakteenk. 14: 128. 1904. 
Solitary, globose, about 5 cm. in diameter, somewhat depressed at apex; tubercles dark green, 
4-angled; spines 6, about 3 mm. long, at first black, changing to gray; flowers and fruit unknown. 
This plant was described from a specimen in the Botanical Garden at Halle of unknown 
origin, but doubtless from Mexico. 
MAMMILLARIA VIPERINA J. A. Purpus, Monatsschr. Kakteenk. 22: 148. 1912. 
Cespitose, decumbent, cylindric, 1.5 to 2 cm. in diameter; tubercles very short, sometimes 
nearly globular; spines numerous, 5 mm. long, whitish brown to brownish black; flowers and fruit 
unknown. 
This plant came from Rio de Zapotitlan, Puebla; we know it only from description 
and the very characteristic published illustration. Quehl, who had seen it, said that it 
was a form of Mammillaria elongata. We believe that it is near M. sphacelata and perhaps 
