178 THE CACTACEAE. 
to 7 cm. long; tube 2 cm. long; inner perianth-segments scarlet to white, oblong, obtuse to acute, 
reflexed; filaments white; style purple throughout; fruit obovoid, 1.5 to 2 cm. long. 
Type locality: Brazil. 
Distribution: Mountains, state of Rio de Janeiro, Brazil. . 
This species has been cultivated widely for many years under various names. It was 
introduced into cultivation about 1818 and, according to Edwards, flowered first in England 
in 1822 and has since been a great favorite as a household plant, blooming freely about 
the end of the year, hence the name Christmas cactus. It is also called crab cactus and 
- ringent-flowered cactus. 
Schumann gives as synonyms of this species Epiphyllum salmoneum and E. spectabile, 
referring them to Cels’s Catalogue, which, however, we have not seen. 
Fics. 185 and 186.—Flowering branch and fruiting joint of Zygocactus truncatus. 
Cereus truncatus altensteinii (Salm-Dyck, Hort. Dyck. 65. 1834) occurs in literature, 
sometimes attributed to Otto, but we have seen no description. We follow Lofgren, who 
refers Zygocactus altensteinit to Z. truncatus. ‘The type came from the Organ Mountains 
near Rio de Janeiro; in 1915, Dr. Rose visited these mountains, where he found the true 
Z. truncatus. 
There are many garden varieties, most of which are very beautiful. Among these are 
Epiphyllum gibsonii, introduced in 1886, with dark orange-red flowers, and Epiphyllum 
guedeneyi, of unknown origin, with large flowers, the outer segments white, tinged with 
sulphur, and the inner ones creamy white; the variety is referred by some to Phyllocactus 
guedeneyi. Nicholson (Dict. Gard. 1: 517) describes some of the best as follows: 
‘“ Bicolor, white, edged with rose; coccineum, ri i 
1 , , ze ; , tich deep scarlet; elegans, bright orange-red, 
centre Tich purple: magnificum, flowers large, white, tips bright rose.colored: roseum, bright rose; 
ceca am KeP reddish purple, with a rich violet centre; salmoneum, reddish salmon; spectabile, 
ite, with delicate purple margin; violaceum superbum, pure white, rich deep purple edge.” 
hi Rampler (Forster, Handb. Cact. ed. 2. 870, 871. 1885) described nine varieties, among 
which are cruentum and tricolor; E. truncatum cruentum was also briefly described by 
Morren (Belg, Hort. 16: 260. 1866). Among other varieties are albiflorum, aurantiacum, 
€randidens, minus, purpuraceum, and vanhoutteanum. 
