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 rhodacanthus 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. 1905. 
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 cm. 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 I 
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. 
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 (Dict. Hort. Bois 472. 1896) as a F1¢. 93.—Denmoza rhodacantha. 
synonym, but neither is described. It is not at all un- a 
likely that Mammillaria coccinea G. Don (Loudon, Hort. Brit. 194. 1830; Cactus coccineus 
Gillies), said to have come from Chile, is also to be referred here. sails 
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 rho aca 1US 
coccineus Monville (Labouret, Monogr. Cact. 304. 1853); Echinopsts rhodacam ta aured 
(Monatsschr. Kakteenk. 17: 76. 1907) and Echinopsis rhodacantha gractlior Laboure 
(Monogr. Cact. 304. 1853). . MG 
Illustrations. Blithende Kakteen 1: pl. 16; Monatsschr. Kakteenk. 4: 187. f. 3; Mollers 
Deutsche Gart. Zeit. 25: 481. f. 12, as Echinopsis rhodacantha. 
Plate vu, 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 1915. 
