85] Cüctaceae. 397 



Lemaireocereus Cartwrightianus Britt. et Rose 1. c. p. 100. — Guayaquil (J. N. 



Rose, J. H. Burns et George Rose n. 21118). 

 L. humilis Britt. et Rose 1. c. p. 101, Textfig. 149—151. — Colombia (Pittier, 



New York Bot. Garden n. 34 794). 

 Leocereus Britt. et Rose gen. nov. in The Cactaceae, vol. II (1920) p. 108 



et App. p. 225. 



In its narrow flower, in the liairs in axils of tlie scales on the ovary 



and tube, this genus siiggests Oreocereiis, but is very different in babit. 



The flower of Leocereus is different from that of Nyctocereus in its narrow 



throat, short periantli-segments, hairy and bristly areoles. 

 L. bahiensis Britt. et Rose 1. c. p. 108, Textfig. 160—161. — Babia. 

 L. melanunis (Schum.) Britt. et Rose 1. c. p. 109 (= Cereus melannriis Scbum.). 



— Brasilia. 



L. Glaziovii (Scbum.) Britt. et Rose 1. c. p. 109 (= Cereus Glaziovii Schum.). 

 Leptocereus Weingartianus (Hartm.) Britt. et Rose in The Cactaceae, vol. II 



(1920) p. 77, Textfig. 112 (= Cereus Weingartianus Hartm.). — Haiti. 

 L. prostratus Britt. et Rose 1. c. p. 79. — Cuba (Shafer n. 13754). 

 L. Maxonii Britt. et Rose 1. c. p. 80, Textfig. 115. — Cuba (Maxon n. 4023, 



Britton et Cowell n. 12 657). 

 L. sylvestris Britt. et Rose 1. c. p. 81. Textfig. 117—118. — Cuba (Britton, 



CoweU et Shafer n. 13060). 

 Machaerocereiis Britt. et Rose gen. nov. in The Cactaceae, vol. II (1920) p. 114. 

 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. 

 M. eruca (Brandegee) Britt. et Rose I.e. p. 115, Textfig. 171, 172 {^Cereus eruca 



Brandegee = Lemaireocereus eruca Britt. et Rose). — Lower California. 

 M. gummosus (Engelm.) Britt. et Rose 1. c. p. 116, Textfig. 173- — 175 {= Cereus 



gummosus Engelm. = C. Cumengei Weber = C. flexuosus Engelm. = 



= Lemaireocereus Cumengei Britt. et Rose = L. gummosus Britt. et Rose). 



— Lower California. 



Mammillaria corbula Herrera in Rev. Univ. Cuzco VIII (1919) p. 61. — Peru. 



Mediocactus Britt. et Rose gen. nov. in The Cactaceae, vol. II (1920) p. 210. 

 In habit and flowers this plant much resembles Hylocereus, but 

 differs from it in its tuberculate ovary and in the felted and spine-bearing 

 areoles of the fruit, which resemble those of Selenicereus. 



M. coccineus (Salm-Dyck) Britt. et Rose 1. c. p. 211, PI. XXXVII, Textfig. 290, 

 291 (= Cereus coccineus Salm-Dyck = C. setaceus Salm-Dyck = C. seta- 

 ceus var. viridior Salm-Dyck = C. Lindbergianus Weber = C. Lindmanii 

 Weber = C. H assler i Schum.). — ■ Brasilia. 



M. megalanthus (Schum.) Britt. et Rose 1. c. p. 212, Textfig. 292 (= Cereus 

 megalanthus Schum.). — Peru. 



Monvillea Britt. et Rose gen. nov. in The Cactaceae, vol. II (1920) p. 21. 

 Type species: Cereus Cavendishii Monville. 



M. Cavendishii (Monville) Britton et Rose 1. c. p. 21, PL III, Fig. 3. 4, Textfig. 

 20, 21 et App. p. 224 (= Cereus Cavendishii MonviUe = C. serpentinus 

 splendens Salm-Dyck = C. Paxtonianus MonviUe = C. splendens Salm- 

 Dyck = C. saxicola Morong = C. euchlorus Weber = C. rhodoleucanthus 

 Schum, = Eriocereus Cavendishii Riccobono). — Argentina and Paraguay. 



