ILLUSTRATIONS. 



1 'LATHS. 



PACING 

 PACE. 



I'I.ATI; i. Group of plants of Cephalocereus macrocepluilus on hillside- near TVhuacan I'mntis] jice. 



I'I.ATI: 2. Ill Top of (lowering stem of Cereus alaci iportanus. (2) Top of stem of Cereus peruvianus. 



(3) Flower of Cereus peruvianus 6 



I'I.ATK 3. (i) Top of stem of Cereus validus. i.-i Top of flowering stem of Cereus validus (3) Topof flow- 

 ering branch of Monvillea cavendishii. (4) Top of branch of M. cavcmlisliii, with fruit. 22 

 I'I.ATI; 4. d) Flowering stem of Cephalocereus pentaedrophorus. (2) Top of stem of Cephalocereus gounel- 

 lei. (3) Top of stem of Ccphaloccreus buliamcnsis, will: llo\vi-r. (4) Fruit of Cepha- 



locercus deeringii 32 



PLATE ,S. A clump of plants of Cephalocereus deeringii on Lower MaU-cumbe Key, Florida 38 



I'I.ATI; 6. (i) Top of flowering stem of Cephalocereus arrabidae. (2) Top of flowering stem of Cephalo- 

 cereus nobilis. (3) Top of flowering stem of Cephalocereus barbadensis. . . 42 



PLATE 7. (i) Plants of Cephalocereus polygonus. (2) Large plant of Cephalocereus chrysacanthus 48 



I'I.ATI; 8. (i) Top of flowering stem of Cephalocereus brooksianus. (2) Top of stem of Cephalocereus ca- 

 tingicola. (3) Top of stem of Cephalocereus phacacanthus. (4) Flowering branch of 



I.eptocereus assurgens 56 



PLATE 9. A large plant of Stetsonia coryne in the desert of northern Argentina 64 



PLATE 10. A plant of Escontria chiotilla, near Tehuacdn, Mexico 66 



PLATE 1 1. Top of flowering plant of Pachycercus chrysomallus 72 



PLATE 12. A mountain-side along Tomellin Canyon, Mexico, covered with Pachycereus columna-trajani. ... 76 

 PLATE 13. (i) Top of flowering branch of Lcptocereus arboreus. (2) Top of stem of Lemaireocereus griseus. 



(3) Fruiting branch of Mediocactus coccineus So 



PLATE 14. (i) Part of branch of Dendroccreus nudiflorus. (2) Flowering branch of Dendrocereus midiflorus. 



(3) Flowering branch of Nyctocereus guatemalensis 1 14 



PLATE is. (i) Top of branch of Eulychnia iquiquen---is. (2) Top of stem of Lemaireocereus dumortieri. 



(3) Part of flowering stem of Nyctocereus serpentinus 118 



PLATE 16. (i) Top of flowering branch of Acanthocereus pentagonus. (2) Top of flowering branch of Acan- 



thocereus subinermis. (3) Top of a fruiting branch of Acanthocereus subinermis. ... 124 

 PLATE 17. (i) End of flowering branch of Heliocereus elegantissimus. (2) End of flowering branch of Helio- 



cereus speciosus. (3) A tip of a fruiting branch of Harri c ia portoricensis 128 



PLATE 18. (0 Tip of a flowering branch of Harrifia eriophora. (2) Fruiting branch of Harrisia criophora. . 148 

 PLATE 19. (i) Top of flowering branch of Harrisia fragrans. (2) Top of fruiting joint of Harrisia fragrans. 



(3) Fruiting branch of Harrisia martinii 150 



PLATE 20. (i) Part of fruiting branch of Harrisia gracilis. (2) Top of flowering branch of Harrisia martinii. 152 



PLATE 21. (i) Flowering branch of Harrisia tortuosa. (2) Fruiting branch of Harrisia tortuosa 156 



PLATE 22. Top of flowering plant of Carnegiea gigantea 164 



PLATE 23. The giant cactus, Carnegiea gigantea, near Tucson, Arizona 166 



PLATE 24. (i) Top of flowering branch of Harrisia fernowi. (2) Flowering branch of Harrisia bonplandii. 



(3) Top of branch of Binghamia melanostele 168 



PLATE 25. (i) Flowering branch of Rathbunia alamosensis. (2) Flowering branch of Rathbunia alamo?ensi?. 

 (31 Top of flowering branch of Borzicactus acanthurus. (4) Top of stem of Arrojadoa 



rhodantha 170 



PLATE 26. (i) Myrtillocactus geometrizans, Tehuacan, Mexico. (2) Myrtillocactus schenckii, near Mitla, 



Mexico 180 



PLATE 27. di End of fruiting branch of Arrojadoa rhodantha. (2) Top of plant of Cleistocactus baumannii. 



(3 ) Flower on branch of Hylocereus stenopterus. 

 PLATE 28. 

 PLATE 29. 

 PLATE 30. 

 PLATE 31. 

 PLATE 32. 



184 



Flower on end of branch of Hylocereus ocamponis 186 



Flower on end of branch of Hylocereus monacanthus 188 



Flower near end of branch of Hylocereus undatus 190 



Flower on short branch of Hylocereus lemairei 192 



(i) Fruit of Hylocereus undatus. (2) Flowering branch of Wilmattea minutiflora. 13) Longitu- 

 dinal section of fruit of Selcniccrcus grandiflorus 196 



PLATE 33. (i) Flowering branch of Selcnicereus grandiflorus. (2) Tip of branch of Scleniccrcus grandi- 

 florus. (3) Fruit of Selenicereus grandiflorus 198 



PLATE 34. Flowering branch of Selenicereus urbanianus 200 



PLATE 35. Flower on branch of Selenicereus coniflorus 202 



PLATE 36. (i) Fruit of Hylocereus trigonus. (2) Flower of Selenicereus boeckmannii. (3) Fruit of Seleni- 

 cereus boeckmannii 204 



PLATE 37. 

 PLATE 38. 



PLATE 39- 



PLATE 4<>. 



Flower of Mediocactus coccineus 



(i) Fruiting branch of Selenicereus pteranthus. (2) Flowering branch of Selenicereus spinulosus. 



i.', I Flowering branch of Weberocereus panamensis 



(i) Flowering branch of Weberocereus tunilla. (2) Flowering branch of Weberocereus biollcyi. 



(31 Flowering branch of Werckleocreeus tonduzii. 141 Flower of Werckleocereus glaber. 



(i) 



214 



216 

 F'lowciing plant of Aporocactus leptophis. (2) Flowering plant of A. flagelliformis 218 



IV 



