48 THE CACTACEAE. 
been much discussion about the identity of the plant; Coulter transferred it to Cereus, 
referring to it Cereus coccineus and C. phoeniceus and assigning to it a wide range, Colorado 
to San Luis Potosi. Rydberg transferred the name to Echinocereus but applied it to the 
same group of plants described by Coulter. A careful restudy of the original illustration 
and Engelmann’s description and a restudy of all the cacti of similar habit in the southwest 
leads us to a different conclusion from that reached by Dr. Coulter and Dr. Rydberg. 
Engelmann, who described it as a Mammillaria, says that it appears to be allied to 
M. vivipara, and this we believe is its true relationship. A Mamumillaria from the region 
about Flagstaff often forms the great clusters mentioned by Engelmann, and while we 
believe that it differs from the one found in northern Arizona it is certainly a near ally, 
probably representing the closely related species from southeastern Arizona and south- 
western New Mexico which has often passed as M. arizonica. 
Engelmann referred a specimen which he had from Sonora to his variety Mammillaria 
vivipara neo-mexicana with the remark that it was ‘‘a form with more spines than any 
other.”’ 
Plate rv shows a clump sent by Mrs. Ruth C. Ross from near Aravaipa, Arizona, in July 
1922. Figure 47 is from a photograph of a single plant obtained by Dr. Rose near Benson 
May 1, 1908, which afterwards flowered in Washington. 
36. Coryphantha cubensis Britton and Rose, Torreya 12:15. 1912. 
Mammillaria urbaniana Vaupel, Monatsschr. Kakteenk. 22: 65. 1912. 
Plants depressed-globose, tufted, 2 to 3 cm. broad, pale green; tubercles numerous, vertically 
compressed, 6 to 7 mm. long, 4 to 5 mm. wide, about 3 mm. thick, grooved on upper side from apex 
to below middle, the groove very distinct; spines about 10, whitish, radiating, acicular but weak, 
3 to 4 mm. long, those of young tubercles subtended by a tuft of silvery white hairs, 1.5 mm. long; 
flowers pale yellowish green, 16 mm. high, the segments acute; filaments, style, and stigma-lobes 
yellowish; fruit red, less than 1 cm. long, naked; seeds black, somewhat angled. 
Type locality: Among stones in barren savanna, southeast of Holguin, Oriente, Cuba. 
Distribution: Type locality and vicinity. 
This species is very inconspicuous and perhaps for that reason is rare in collections. 
It has only twice, to our knowledge, been collected, both times by Dr. J. A. Shafer, once in 
1909 (No. 2946) and again in 1912 (No. 12432), who gave a short account of its discovery in 
the Journal of the New York Botanical Garden (No. 155). He states that it barely pro- 
trudes through the layer of broken stones that filled the interstices between the larger 
rocks; that the largest plants were scarcely an inch in diameter, one of them bearing a 
small yellowish flower. It lives only a short time in greenhouse cultivation. 
On account of the name Mammillaria cubensis Zuccarini (Labouret, Monogr. Cact. 59. 
7853) Vaupel gave a new specific name to the plant when he transferred it trom Cory- 
phantha. 
Plate v, figure 1, shows the plant collected by Dr. Shafer in 1912 which flowered in the 
New York Botanical Garden in July of the same year; figure 1a shows the fruit and figure 1b 
shows a tubercle from the same plant. 
37. Coryphantha sulcata (Engelmann). 
>Mammillaria sulcata* Engelmann, Bost. Journ. Nat. Hist. 5: 246. 1845. 
Mammillaria strobiliformis Mithlenpfordt, Allg. Gartenz. 16: 19. 1848. Not Engelmann, 1848: 
~Mammillaria calcarata Engelmann, Bost. Journ. Nat. Hist. 6: 195. 1850. 
Coryphantha calcarata Lemaire, Cactées 35. 1868. 
Cactus calcaratus Kuntze, Rev. Gen. Pl. 1: 259. 1891. 
Cactus scolymotdes sulcatus Coulter, Contr. U. S. Nat. Herb. 3: 116. 1894. 
Mammillarta radians sulcata Schumann, Gesamtb. Kakteen 496. 1898. 
Cactus sulcatus Small, Fl. Southeast. U.S. 812. 1903. 
Cespitose, 8 to 12 cm. in diameter; tubercles rather large, 10 to 12 mm. long, somewhat flat- 
ened, soft; radial spines acicular, straight, white; central spines several, one somewhat stouter 
* Forster (Handb. Cact. 255. 1846) credits such a name to Pfeiffer but it is without description. 
