THE CACTACEAE. 



Figure 145 shows a plant, growing on the flats of the Catamayo Valley, southern 

 Ecuador, photographed by George Rose in 1918; figure 146 is from a photograph taken by 

 Mrs. J. N. Rose at Matucana, Peru; figure 147 shows its flower and figure 148 its fruit. 



19. Lemaireocereus cartwrightianus sp. nov. 



Plant 3 to 5 meters high, with woody 

 trunk, much branched; branches consisting 

 of short stout joints, 15 to 60 cm. long, 8 to 15 

 cm. in diameter ; ribs 7 or 8 ; areoles large, brown- 

 felted; young spines white, brown, black, or 

 variegated, about 20, 1 to 2 cm. long, except on 

 the old trunk and here 12 em. long or more; 

 flowers slender, 7 to 8 cm. long, opening in 

 the early evening; outer perianth-segments 

 narrow, 1 to 1.5 cm. long, reddish, erect ; inner 

 perianth-segments small, white except at the 

 spreading tips; filaments numerous, short, 

 included; fruit globular to oblong, S to 9 cm. 

 long, covered with clusters of weak spines, de- 

 ciduous when ripe, red without, white within. 



Very common on the flats near Guaya- 

 quil; collected by J. N. Rose, J. H. Burns, 

 and George Rose, north of the city, August 

 n, 1918 (No. 21118). It is characterized 

 by very narrow flowers. 



Fig. 147. — Flower of Lemaireocereus laetus. Xo.6. 

 Fig. 148. — Fruit of same. Xo.6. 



It is named for Mr. Alfred Cartwright who has for many years been connected with 

 the British Consular Service at Guayaquil and who has aided many visiting scientists. 

 Mr. Cartwright first described this plant to us and directed us to its peculiar habitat. 



