LEMAIRROCEREUS. 85 



had been mixed with other species, but Dr. Rose, who studied the Philippi collection in 



1914, was able to make the separation, and through the kindness of the Director, brought 

 back a flower and cluster of spines, which are now preserved in the United States National 

 Herbarium in Washington. From 1862 to 19 14 there is no record that this species has been 

 seen by botanists. Dr. Rose, while exploring in Chile, after several efforts was finally 

 successful in obtaining living, herbarium, and formalin material (No. 19393), an d a l so a 

 fairly good photograph. 



Figure 124 shows a flower collected by Dr. Rose at the type locality in 19 14. 



12. LEMAIREOCEREUS Britton and Rose, Contr. U. S. Nat. Herb. 12: 424. 1909. 

 Sleiwcereus Riccobono, Boll. R. Ort. Bot. Palmero 8: 253. 1909. 



Plants usually large, tall, and branching, but rarely low, nearly prostrate, simple, forming 

 thickets; areoles rather large, felted; spines usually stout and numerous; flowers diurnal or in some 

 species nocturnal, one at an areole, tubular-funnelform or eampanulate, the short tube tardily 

 separating with the style from top of the ovary; stamens numerous, borne in many rows all along 

 the inner surface of the throat; ovary more or less tubercled, bearing scales felted in the axils, the 

 areoles at first spineless or nearly so, soon developing a cluster of spines; fruit globular to oval, often 

 edible, irregularly bursting when old, exposing the seeds, at first very spiny, but when ripe the 

 spines are often deciduous; seeds many, black. 



The genus commemorates Charles Lemaire (1801-1871), a distinguished French 

 cactologist and horticulturist; it consists of about 21 species, distributed from southern 

 Arizona and Cuba to Peru and Venezuela. 



Type species : Cereus holliamis Weber. 



Key to Species. 



A. Ribs 6 to 20, separated by deep intervals. 



B. Areoles with white, brown, or gray felt, not glandular. 

 Spines slender, acicular to subulate. 



Spines not appressed to the joints, a central one usually evident. 

 Ribs 6 to 12. 



Areoles borne on ribs, when these are crenate borne on elevations. 

 Joints green, not glaucous. 



Flowers 10 cm. long; central spine long, reflexed 1. L. holliamis 



Flowers 7 to 9 cm. long; central spine spreading or 



ascending 2. L. hystrix 



Young growth glaucous, the bloom persistent as curved, 

 whitish streaks. 

 Spines subulate; plants relatively light green. 



Ribs 8 to 10; young growth slightly glaucous 3. L. griseus 



Ribs 6 or 7 ; young growth definitely glaucous. 



Spines terete, 5 cm. long or less 4. L. pruinosus 



Spines flattened above, up to 8 cm. long 5. L. longispimts 



Spines acicular; plants dark green 6. L. eichlamii 



Areoles borne in depressions of the crenate ribs. 

 Plants bright green. 



Flowers greenish yellow to rose. 



Ribs 9 to 12 ; flowers greenish yellow 7. L. chichipe 



Ribs 7 to 9; flowers rose-colored 8. L. chende 



Flowers white 9. L. godingianus 



Plants glaucous, the bloom persistent as whitish streaks. 



Ribs 6 to 8, bluntly acute 10. L. aragonii 



Ribs 8 to 12, rounded 11. L. stellalus 



Ribs about 20 12. L. treleasei 



Spines usually all radial, appressed to the joints 13. L. deficiens 



Spines very stout, at first reddish brown or nearly black 14. L. weberi 



BB. Areoles with dark brown or black felt, glandular. 

 Ribs 6 to 8. 



Scales of the ovary 2 mm. long or less 15. L. queretaroensis 



Scales of the ovary 4 to 6 mm. long 16. L. montanus 



Ribs 12 to 17 17. L. thurberi 



A. Ribs 3 to 7, separated by broad and shallow intervals. 

 Areoles large, widely separated. 

 Stems very stout, erect. 



Stems bluish gray; spines of fruit brown 18. L. laelus 



Stems green; spines of fruit yellow 19. L. cartwrightianus 



Stems slender, weak, usually 3 or 4-ribbeu 20. L. humilis 



Areoles small, nearly contiguous 21. L. dumorlieri 



