ii 4 



THE CACTACEAE. 



reproduced (see fig. 169), was obtained only after cutting away a large number of bushes 

 in order to place the camera. 



The Cuban name for this plant is fior de copa. 



Illustrations: Contr. U. S. Nat. Herb. 12: pi. 49 to 51 ; Journ. N. Y. Bot. Gard. 10: f. 

 19; Roig, Cact. Fl. Cub. pi. 2, as Cereus nudiflorus. 



Plate xiv, figures 1 and 2, show branch and flower of the plant as it flowered at the 

 New York Botanical Garden in 191 1. Figure 169 is from a photograph taken by Marshall 

 A. Howe at Guantanamo Bay, Cuba, in 1909; figure 170 shows a fruit collected by N. B. 

 Britton and Percy Wilson at Punta Colorado, Cienfuegos Bay, Cuba, in 1910. 



Fig. 169. — Dendrocereus nudiflorus. 



-Fruit of D. nudiflorus. 

 X0.5. 



19. MACHAEROCEREUS gen. nov. 



Plants prostrate or low and bushy, often with long horizontal or prostrate stout branches, very 

 spiny throughout; ribs low; areoles large, felted, and spiny; spines numerous, the centrals flattened 

 and dagger-like; flowers diurnal, 1 at an areole, long, slender, funnelform, the perianth persisting 

 on the fruit; stamens numerous, borne on the narrow elongated throat; ovary and lower part of 

 flower-tube bearing many small scales, these subtending felted areoles which afterwards bear clusters 

 of spines ; fruit globular, edible when young, covered with clusters of spines, but when fully mature 

 becoming naked ; seeds dull black, somewhat punctate, acute on the back. 



In its fruit this genus is nearest Lemaireocereus , to which we once referred its two 

 species; the perianth, however, is much more elongated and more persistent; in habit and 

 shape of spines the species are very different from any of Lemaireocereus. 



Two species, natives of Lower California, are recognized, of which Cereus eruca Bran- 

 degee is the type. 



The generic name is from the Greek, signifying dagger-cereus, with reference to the 

 dagger-like spines. 



Key to Species. 



Prostrate, the tips ascending; flowers yellow '. i. M. eruca 



Bushy, erect, 1 meter high or less; flowers purple 2. M. gummosus 



