DISCOCACTUS. 217 



The generic name is from Sutkos disk, and kolktos, referring to the flattened, disk-like 

 shape of the plant body. 



Key to Species. 



Plant-body spineless or nearly so 1. D. subnudus 



Plant-body very spiny. 



Cephalium composed of long wool and many erect bristles. 



Ribs 12 to 16; perianth-segments acute 2. D. hartmannii 



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. bahknsis 



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. 



?> 



*JS 



Fig. 230. Discocactus hartmannii. 



Fig. 231. Cactus broadwayi. 



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: Bliihende 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. 



