DISCOCACTUS. 217 
The generic name is from dicxos disk, and Kax7os, referring to the flattened, disk-like 
shape of the plant body. 
KEY TO SPECIES. 
Plant-body spineless or nearly soO.... 2... 0000 c ete e cece ve veeeveeey 1. D. subnudus 
Plant-body very spiny. 
Cephalium composed of long wool and many erect bristles. 
Ribs 12 to 16; perianth-segments acute....... 0.0.0.0 0c cece ccc cece cece eee, 2. D. hartmannii 
Ribs 9 to 11; perianth-segments so far as known obtuse. 
Ribs made up of large tubercles.............. 00.0000 c cece eee cee eee sess. 3. D. heptacanthus 
Ribs made up of indistinct tubercles...........000.0.000.00 0 ccc cece eee ee ee 4. D. alteolens 
Cephalium with few bristles or none. 
Spines acicular......... 0. 0 cece e ect eee e becca es 5. D. sehntneri 
Spines stout. 
Spines flattened... 0.00. eect eee cece eens 6. D. placentiformis 
Spines terete... 0... eee n tenet ene b eee ees 7. D. bahiensis 
1. Discocactus subnudus sp. nov. 
Plant simple; ribs few (perhaps 8 or 9), somewhat flattened, divided into tubercles, spineless 
or nearly so; cephalium small, containing many erect bristles; flowers large. 
This species, according to Dr. Albert Lofgren, is to be found in the sands along the 
coast at Bahia, Brazil, but, unfortunately, Dr. Rose did not find it while he was there in 
1915, although he searched for it repeatedly. Dr. Lofgren has furnished us, however, a 
very characteristic photograph from which the above description is drawn. 
Figure 228 is from a photograph taken by Dr. Lofgren. 
Fic. 231.—Cactus broadwayi. 
Fic. 230.—Discocactus hartmannii. 
» 2. Discocactus hartmannii (Schumann). 
Echinocactus hartmannii Schumann, Monatsschr. Kakteenk. 10: 170. 1900. 
Plants simple, broader than high, green, shining, crowned by a brown bristly cephalium, ribs 
12 to 16, broad at base, obtuse, divided transversely into large tubercles; spines yen , su ate; 
radial spines 6 to 12, curved backward and appressed ; central spines solitary ; flower-tu ” junne orm, 
bearing a few spreading scales; outer perianth-segments green; inner perianth se gmen s lance 
to nearly oblong, white; fruit yellow, thin-skinned; seeds globular, 2 mm. 1n diameter. 
Type Locality: Campos am Capivary, Paraguay. 
Distribution: Paraguay. jeseripti illustrations only 
The plant is known to us from description and llustra y. _ 
I llustrations: Blithende Kakteen 2: pl. 69; Schumann, Gesamtb. Kakteen Nachtr. 
f. 12, 13; Monatsschr. Kakteenk. 10: 171, IT: 184, as Echinocactus hartmanni. 
Figure 230 is a reproduction of the first illustration cited above. 
