DISCOCACTUS. 
217 
The generic name is from 8U tkos disk, and kclktos, referring to the flattened, disk-like 
shape of the plant body. 
Key to Species. 
Plant-body spineless or nearly so. 1. D. siibnudus 
Plant-body very spiny. 
Cephalium composed of long wool and many erect bristles. 
Ribs 12 to 16; perianth-segments acute. 2. D. liartmannii 
Ribs 9 to 11; perianth-segments so far as known obtuse. 
Ribs made up of large tubercles. 3. D. heptacanthus 
Ribs made up of indistinct tubercles. 4. D. alteolens 
Cephalium with few bristles or none. 
Spines acicular. 5. D. zehntneri 
Spines stout. 
Spines flattened. 6. D. placentiformis 
Spines terete. 7. D. bakiensis 
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 Dofgren, 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. Dofgren has furnished us, however, a 
very characteristic photograph from which the above description is drawn. 
Figure 228 is from a photograph taken by Dr. Dofgren. 
Fig. 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 yellow, subulate; 
radial spines 6 to 12, curved backward and appressed; central spines solitary; flower-tube funnelform, 
bearing a few spreading scales; outer perianth-segments green; inner perianth-segments lanceolate 
to nearly oblong, white; fruit yellow, thin-skinned; seeds globular, 2 mm. in diameter. 
Type Locality: Campos am Capivary, Paraguay. 
Distribution: Paraguay. 
The plant is known to us from description and illustrations only. 
Illustrations: Bluhende Kakteen 2: pi. 69; Schumann, Gesamtb. Kakteen Nachtr. 
f. 12, 13; Monatsschr. Kakteenk. 10: 171; 11: 184, as Echinocactus hartmannii. 
Figure 230 is a reproduction of the first illustration cited above. 
Fig. 231.—Cactus broadwayi. 
