I20 



THE CACTAC^AE. 



5. Nyctocereus oaxacensis sp. nov. 



Stems branching, slender, 2 to 3 cm. in diameter; ribs 7 to 10, rather low; areoles 10 mm apart; 

 radial spines 8 to 12, 4 to 15 mm. long, slender, brownish; centrals 3 to 5; flowers 8 to 10 cm. long, 

 *' whitish inside, dirty purplish or reddish outside"; perianth-segments linear to oblong, rounded at 

 apex; stamens not extending nearly as far as the perianth-segments; ovary densely covered with 

 brownish bristly spines. 



Collected by E. W. Nelson about Lagunas, Oaxaca, Mexico, altitude 255 meters, 



June 5, 1895 (No. 2543, type). 



We refer here tentatively another specimen also collected by Mr. Nelson near Huilo- 



tepee, Oaxaca, altitude 30 meters, May 4 to 11, 1895 (No. 2585). 





-^ 



Fig. 178.— Nyctocereus guatemalensis, as it flowered in Washington. 



^9 



\ 



\ 



BRACHYCEREUS 



vStems low, forming candelabrum-like masses; branches numerous, cylindric; ribs many, low, 

 with closely set areoles bearing felt and numerous acicular spines ; flowers narrow-funnelf orin, bear- 

 ing small scales which subtend large spiny areoles ; outer perianth-segments lanceolate ; inner perianth- 

 segments very narroxy, long-acuminate, described as possibly white but more likely yellow; filaments 



very short; ovary oblique y subglobose, bearing scattered spinv areoles; fruit ellipsoid, very spiny, 

 but in age probably naked. v ^ 3 v j 



AlA 



from 



/ 



1. 



Only one species is known, native of the Galapagos Islands. 



cereus thouarsii (Weber). 



Cereus thouarsii Wcher. Bull. Mus. Hist. Nat. Paris SMi^ 

 Lereus neswUcus Schumann in Robinson, Proc. Amer. Arad 



1899. 

 38: 179 



1902 



