1 90 



Tlllv CACTAClCAIi. 



10. Hylocereus monacanthus (Lemaire). 



(Vn'H.t monacanthus Lemaire, Hurt. 1'niv. 6:60. 1845. 



Stems green, 3-angled, the margins undulate; areoles remote, about 3 cm. apart, tomentose; 

 spines usually single, sometimes 2, rigid, much swollen at base; flowers funnelform, large, 28 cm. 

 long, 17 cm. broad; ovary and tube covered with large scales; outer perianth-segments narrow, 

 -nniish; iniiiT perianth-segments oblong-ovate; filaments numerous, about 200, 8 to 9 cm. long, 

 white but rose-colored at base; style thick, exserted, yellow; stigma-lobes numerous, spreading. 



Type locality: Colombia. 



Distribution: Colombia and Panama. 



This species was first introduced by Cels and published in 1845. It was again intro- 

 duced by Werckle in 1905 and fully described by Weingart in 1911. Both Dr. Weber and 

 Dr. Schumann considered it to be a variety of Cereus martini i. 



A flower observed at the New York Botanical Garden September 6, 1918, and a plant 

 brought by Dr. M. A. Howe from the Urava Islands in 1912, showed 2-forked stigma-lobes, 

 the forks 2 to 3 mm. long; other flowers, previously observed, showed simple stigma-lobes. 



Plate xxix shows a branch of the plant collected by Dr. Howe, on Urava Island, Bay 

 of Panama, in 1912, which flowered in the New York Botanical Garden in 1915. 



FIG. 267. Hylocereus stenopterus. 



1909. 



11. Hylocereus stenopterus (Weber) Britton and Rose, Contr. U. S. Nat. Herb. 12: 429. 

 Cereus stenopterus Weber, Bull. Mus. Hist. Nat. Paris 8: 458. 1902. 



A weak vine, not rooting freely from the sides, at least in cultivation, the joints 4 cm. broad, 

 light green in color, not glaucous; ribs 3, thin; areoles slightly elevated; spines i to 3, small, yellow; 

 flower 10 to 12 cm. long, opening at night, closing very early (completely closed at 9 a. m.); tube 

 short, about 2 cm. long; perianth-segments all similar, reddish purple, linear, about 7 cm. long; 

 stamens short, exserted; style white, thick, much exserted; stigma-lobes white, when closed form- 

 ing an ovoid acuminate cluster; scales on ovary and flower-tube orbicular or the upper ones narrowly 

 ovate, green, with purple margins. 



Type locality: Vallee de Tuis, Costa Rica. 



Distribution: Costa Rica, Central America. 



This species is common in Costa Rica, and in recent years has been widely distributed 

 by several Costa Rican collectors; it grows well under glass, and flowers frequently. It is 

 the only Hylocereus in cultivation with red flowers except H. extensus. 



Plate xxvii, figure 3, is from a plant obtained by Mr. William R. Maxon in San Jose, 

 Costa Rica, in 1906, which flowered at the New York Botanical Garden. Figure 267 is 

 from a photograph of a specimen which flowered in Washington from specimens received 

 from the New York Botanical Garden in 1910 (No. 22197). 



