sicuexiciikicrs. 



209 



marly terete, with 6 to u faint ribs; areoles minute, each bearing a small tuft of felt subtended by 

 a small scale but no spines; flower 15 to 16 em. long, bright red; outer perianth-segments narrow, 

 greenish, spreading; inner perianth-segments 

 oblong; flower-tube narrow; style green at 

 base, pink in the middle, nearly white above; 

 ovary spiny; fruit ovoid, yellow, bearing clus- 

 ters of brown spines at the areoles. 



Type locality: Cerro Mogote, near 

 Miravalles, Costa Rica. 



Distribution: Costa Rica. 



It resembles some species of Rhipsalis 

 in its epiphytic habit and in its long, slender, 

 naked branches, but not in its flower. In 

 its naked stems, large flowers, and spiny 

 fruit it resembles 5. incrmis, but differs 

 from it in its many low ribs. We have had 

 this plant under observation for a number 

 of years but it has flowered only once. We 

 have seen a second flower which Mr. Oton 

 Jimenez brought us in alcohol from Costa 

 Rica in 1 9 1 9 . He states that even in Costa 

 Rica the plant rarely flowers. 



Figure 288 shows branches of Seleni- 

 cereus wercklei from a plant grown in 

 Washington which was sent from Costa 

 Rica by O. Jimenez; figure 289 shows a 

 plant which flowered in the New York 

 Botanical Garden in 1918. 



DESCRIBED SPECIES, PERHAPS OF THIS GENUS. 



Cereus acanThosphaera Weingart, Monatsschr. Kakteenk. 24: Si. 19 14. 



"Dark green, climbing in trees and hanging down, branched at the base; branches uniform, 

 3 to 7 meters long, with narrow, short, equal, rectangular joints and 4 or 5 compressed-winged 

 ribs; sinuses acute; areoles small, with scanty shining tomentum; spines acicular, 1 to 3, diverging, 

 short, and brownish above; flower unknown; fruit large, round, pendent, yellowish green, pilose and 

 very spiny, crowned by the rotting perigon." 



Type locality: On Rio de Santa Maria, State of Vera Cruz, Mexico. 

 Distribution: Known only from the type locality, and to us only from the description. 

 It may be a near relative of Deamia testudo. In Mexico the two plants are found 

 in the same river valley. 



Cereus humilis De Candolle, Prodr. 3: 46S. 1828. 



Plant low, 2.5 cm. in diameter, with spreading, elongated, rooting branches; ribs 4 or 5, strongly 

 compressed, repand; areoles 8 mm. apart, bearing white felt or nearly naked; spines 4 to 8 mm. long; 

 radial spines 8 to 12, setaceous, white; central spines 3 or 4, stouter than the radial, straw-colored. 



This species was described by De Candolle in 1828, who stated that the flowers and 

 the country from which it came were unknown. Salm-Dyek had also sent it to him as a new 

 species, under the name of Cereus gracilis. In 1837, Pfeiffer redescribed the species, adding 

 the variety minor Pfeiffer (Enum. Cact. 115), which latter he described as having fasci- 

 culate, slenderer branches and subsetaceous spines. He gave as synonyms of this variety 

 Cereus mariculi Hortus and C. myriacaulon Martius, sometimes misspelled nyriacaulon. 



