THE CACTACEAE. 



buds covered with long white hairs; flower 25 cm. long; outer perianth-segments narrow, in 2 or 3 

 series, brown, or inner series yellowish, acuminate, 8 to 9 cm. long; inner perianth-segments shorter 

 and broader than the outer, pure white, entire, acute; filaments numerous, included; style not pro- 

 jecting beyond the stamens, 17 to 18 cm. long; stigma-lobes linear, about 20; scales on the ovary and 

 tube spreading, 4 to 6 mm. long; fruit not known. 



Collected by Dr. J. A. Shafer on Cayo Romano, Cuba, in 1909 (No. 281 1). 



This species is clearly distinct from 5. boeckmannii. Both flowered May 2, 1915, in 

 Washington, when decided differences were observed in the color of the hairs on the flower- 

 tube and in the color of the outer perianth-segments. 



Figure 278 is from a photograph of a branch of the type plant. 



Fig. 2 78. — Selenicereus brevispinus. 



9. Selenicereus boeckmannii (Otto) Britton and Rose, Contr. U. S. Nat. Herb. 12: 429. 1909. 



Cereus boeckmannii Otto in Salm-Dyck, Cact. Hort. Dyck. 1849. 217. 1850. 

 Cereus irradians Lemaire, Illustr. Hort. 11: Misc. 74. 1864. 

 Cereus eriophorus Grisebach, Cat. PI. Cub. 116. 1866. Not Pfeiffer, 1837. 

 Cereus vaupelii Weingart, Monatsschr. Kakteenk. 22: 106. 1912. 



Stems light green, 1 to 2 cm. in diameter, strongly angled; ribs 3 to 8, slightly if at all undulat- 

 ing; areoles at first brownish but white in age; spines and hairs in the areoles at first purplish, the 

 spines 3 to 6, becoming yellowish, 2 mm. long or less; flowers not fragrant, 24 to 39 cm. long; outer 

 perianth-segments and scales linear, brownish; inner perianth-segments oblanceolate, 10 cm. long 

 by 3 cm. broad at widest place, pure white; tube and throat 14 cm. long, bearing scattered, short, 

 linear, acute, reddish scales, their axils bearing long brown silky hairs and brown bristles; filaments 

 greenish, long, slender, and weak ; style greenish, about 4 mm. in diameter ; ovary strongly tuberculate ; 

 fruit globular, 5 to 6 cm. in diameter. 



Type locality: Not cited. 



Distribution: Cuba, Hispaniola, and eastern Mexico; introduced into the Bahamas. 



Illustration: Roig, Cact. Fl. Cub. pi. 3, f. 3. 



Plate xxxvi, figure 2, shows a specimen collected by J. A. Shafer on Cayo Guayaba, 

 Cuba, in 1909, which flowered in the New York Botanical Garden, May 14, 1913; figure 

 3 is from a specimen collected in Cuba by Dr. Britton, which flowered and set fruit in 1915. 



Piece of branch of S. macdonalilkic. 



10. Selenicereus macdonaldiae (Hooker) Britton and Rose, Contr. U. S. Nat. Herb. 12: 430. 1909. 

 Cereus macdonaldiae Hooker in Curtis's Bot. Mag. 79: pi. 4707. 1853. 

 The oldstems always terete, ioto 15 mm. in diameter; younger stems somewhat 5-angled, giving 

 off aerial roots, with rather prominent, flattened tubercles 1 to 5 cm. apart, 2 to 3 mm. high; spines 



