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XIV ILLUSTRATIONS. 



Facing page. 



Plate 45. Talinum diffusion Rose & Standley . . 287 



46. View at Nogales, showing scanty vegetation 292 



47 . View at Nogales, showing bear grass (Nolina) and scrub oaks 292 



48. Yucca brerifolia and an oak at Nogales 293 



49. Cowania stansburiana, a characteristic desert shrub at Nogales 293 



50. Echeveria gloriosa Rose 295 



51. Echeveria gloriosa Rose 295 



52. Graptopetalon pusillum Rose 296 



53. Sedum compactum Rose 297 



54. Sedum farinosum Rose 297 



55. Sedum humifusum Rose 298 



56. Sedum liebmannianum Hemsl 299 



57. Sedum mellitulum Rose 299 



58. Sedum pachyphyllum Rose 299 



59. Sedum rhodocarpum Rose 300 



60. Sedum treleasei Rose 300 



61 . Pachyphytum compactum Rose 301 



62. Ariocarpus fissuratus (Engelm.) Schum 308 



63. Ariocarpus lloydii Rose 308 



64 . Opuntia ballii Rose 309 



65. Opuntia dcamii Rose 309 



66. Opuntia eichlamii Rose 310 



67. Opuntia macJcenscnii Rose 310 



68. Gyrophora polyphylla (L.) Borr. & Turn, and G. rugifera (Nyl.) Th. 



Fries 315 



69. Gyrophora reticulata (Schaer.) Th. Fries 316 



70. Gyrophora vellca (L.) Ach. and G. polyrhiza Koerb 317 



71. Gyrophora hyperborea (Hoffm.) Ach 319 



72. Gyrophora phaea (Tuck. ) Herre 320 



73. Umbilicaria pustulata (L. ) Hoffm 321 



74. Neca tenuis Standley 384 



75. A. Fruit of Okenia hypogaea Schlecht. & Cham. B. Pisonia capitata 



(S. Wats.) Standley 388 



76. Okenia grandiflora Standley 397 



77. Quamoclidion multifiorum Torr 411 



78. Olmedia caucana Pittier 434 



79. Olmedia caucana Pittier 434 



80. Pcrebea castilloidcs Pittier 438 



81 . Perebea castilloidcs Pittier 438 



82. Naucleopsis macrophylla Miq 440 



83. Naucleopsis naga Pittier 440 



84 . Naucleopsis naga Pittier 440 



85. Naucleopsis naga Pittier 440 



86. Licania platypus TTemsl _ 443 



87. Couepia Jloccosa Fritsch 445 



88. Couepia Jloccosa Fritsch 445 



89. Fruit of Sterculia carthagenensis C'av 448 



90. Mammea americana L 451 



91. Fruit of Mammea americana L 451 



92. Rhredia madruno Planch. & Triana 455 



93. Rhecdia madruno Planch. & Triana 455 



94. Rhecdia madruno ovata Pittier 451; 



95. Fruit of Rhecdia madruno bituberculata Pittier 456 



96. Seeds of Sideroxylon spp 450 



