DENMOZA. 



79 



rather narrow flowers and exserted stamens there are suggestions of Cleistocactus , but the 

 plant body is very different. It is more like some species of Echinopsis, to which, however, 

 its flowers show little resemblance. It has no close relationship to Cereus or Cephalocereus . 

 Denmoza differs from all other genera in this subtribe in producing long bristle-like 

 spines from the flowering areoles of very old plants. 



1. Denmoza rhodacantha (Salm-Dyck). 



Echinocactus rhodacanthus Salm-Dyck, Hort. Dyck. 341. 1834. 

 Echinopsis rhodacantha Salm-Dyck, Cact. Hort. Dyck. 1849. 39. 1850. 

 Cleistocactus rhodacanthtis Lemaire, Illustr. Hort. 8: Misc. 35. 1861. 

 Pilocereus erythrocephalus Schumann, Gesamtb. Kakteen 195. 1897. 

 Cereus erythrocephalus Berger, Rep. Mo. Bot. Gard. 16: 69. 1905. 

 Pilocereus rhodacanthus Spegazzini, Anal. Mus. Nac. Buenos Aires III. 4: 485. 



i95- 



Simple, at first globular, often 3 to 6 dm. long, but becoming elongated, and when of great age 

 1.5 meters high and 3 dm. in diameter; ribs 15 to 20 or even 30, broad at base, separated by narrow 

 intervals, about 1 em. high; young areoles felted, circular, when old 8 to 10 mm. in diameter, usually 

 1 to 2 cm. apart, but on very old plants approximate, perhaps confluent ; spines very different on 

 young and very old plants; spines on small plants 6 to 12 at 

 each areole, white or reddish, subulate, more or less curved, 

 4 cm. long or less; central spine, if present, solitary; spines 

 on the top of old plants slender and longer, 7 cm. long, often 

 accompanied by a row of 10 or more long brown bristles; 

 flowers slender, 4 to 5 cm. long; ovary and flower-tube bear- 

 ing small, triangular to lanceolate, appressed, acute scales 

 with long white hairs in their axils; perianth-segments small, 

 apparently connivent; filaments red, exserted for at least 1 

 cm. beyond the tube; style red, exserted; wool at base of 

 throat matted, 6 to 8 mm. long; fruit 2 cm. in diameter, nearly 

 smooth in age; seeds oblique, 1.5 mm. in diameter. 



Fig. 93. Denmoza rhodacantha. 



Type locality: Not cited at place of publication, 

 but doubtless Mendoza, Argentina. 



Distribution : Western mountains of Argentina. 



Vaupel (Monatsschr. Kakteenk. 31: 13. 1921) 

 gives an interesting description of the species which 

 flowered in Berlin in 1920 where it is grown as Cereus 

 erythrocephalus. 



Pfeiffer gives Echinocactus coccineus (Enum. Cact. 

 50. 1837) as a synonym, while Weber gives Cereus 

 rhodacanthus Weber (Diet. Hort. Bois 472. 1896) as a 

 synonym, but neither is described. It is not at all un- 

 likely that Mammillaria coccinca G. Don (Loudon, Hort. Brit. 194. 1830; Cactus coccineus 

 Gillies), said to have come from Chile, is also to be referred here. 



Schumann refers here Echinopsis aurata Salm-Dyck and Echinocactus dumesnilianus 

 Cels but these references are very doubtful ; they probably belong to Eriosyce ceratistes. 



The following varieties have been referred to this species: Echinocactus rhodacanthus 

 coccineus Monville (Labouret, Monogr. Cact. 304. 1853), Echinopsis rhodacantha aurea 

 (Monatsschr. Kakteenk. 17: 76. 1907) and Echinopsis rhodacantha gracilior Labouret 

 (Monogr. Cact. 304. 1853). 



Illustrations: Bliihende Kakteen 1: pi. 16; Monatsschr. Kakteenk. 4: 187. f. 3; Mollers 

 Deutsche Gart. Zeit. 25: 481. f. 12, as Echinopsis rhodacantha. 



Plate viii, figure 2, shows a flower of a plant brought by Dr. Rose to the New York 

 Botanical Garden in 1915, which bloomed in 1917. Figure 93 is from a photograph taken 

 by Paul G. Russell at Mendoza, Argentina, in 19 15. 



