CONTENTS. 
Page 
Introduction ..............-22.2.2. 2-2-2 e eee ee ee eee eee 303 
Systematic treatment .........-.-. ----------------- 2-22-22 eee eee eee 305 
ILLUSTRATIONS. 
PLATES. 
: Facing page. 
Plate XXVIII. Abronia insularis Standley .......--.---------------- ------ 312 
XXIX. Abronia acutalata Standley and A. minor Standley .....-..--- 312 
XXX. Abronia breviflora Standley ..........2....---..------------- 312 
XXXI. Abronia variabilis Standley and A. sparsifolia Standley... .--. 314 
XXXIL. Abronia neurophylla Standley ............--.--------------- 314 
XXXII. Abronia platyphylla Standley ..........-------------------- 314 
XXXIV. Abronia covillei Heimerl.............-..------------------- 316 
XXXV. Abronia bigelovii Heimerl .......---.-- wee eee eee eee eee eee 317 
XXXVI. Abronia exalata Standley and A. turbinata Torr ......-.----- 318 
XXXVII. Abronia arizonica Standley and A. lobatifolia Standley ....--. 319 
XXXVIIIL. Abron torreyi Standley ..........-.-.-------------------- 320 
XXXIX. Abronia ramosa Standley ............----------.----------- 321 
XL. Abronia glabrifolia Standley and A. orbiculata Standley... ..- 321 
XLI. Abronia nealleyi Standley and A. terana Standley......-.-.--- 323 
XLII. Abronia robusta Standley .........----.-------------------- 324 
XLII. Abronia fendleri Standley.......--.------------------------ 324 
TEXT FIGURES. 
Page. 
Fig. 49. Fruit of Abronia latifolia ...............--------------------------- 311 
50. Fruit of Abronia maritima...........--.--.---2-------------- 2-2 -- 311 
51. Fruit of Abronia alba .........-..-..------ 2-2-0222 eee 312 
52. Fruit of Abronia umbellata............2.---.------------ 2-2-2 +e 313 
53. Fruit of Abronia gracilis. ........----- Lee ee eee ee eee eee eee 315 
54. Fruit of Abronia villosa ....-....------------.------------------ .... 3d 
55. Fruit of Abronia aurita......2./----------- 2-0 eee ee eee eee eee 316 
56. Fruit of Abronia pinetorum _.-....--------------------------------- 316 
57. Fruit of Abronia pogonantha ......2....---.--------------- +e eee 316 
58. Fruit of Abronia alpina ..........-------------------- 2-2 eee eee 316 
59. Fruit of Abronia glabra .....----.----------------------- +--+ +--+ 321 
60. Fruit of Abronia elliptica...........----------- 22-20-02 ee eee eee 322 
61. Fruit of Abronia salsa.......--.--------2------------ Lice eee eee eee 323 
62. Fruit of Abronia fallaw......-..22-------------- Lecce eee eee eee eee 323 
63. Fruits of Abronia fragrans....-.---..-----.---------------++-+-+---- 325 
64. Fruit of Abronia nudata.......-......------2 52-2522 eee eee 326 
65. Fruit of Abronia ammophila ........-..------------------- ++ --ee- 326 
66. Fruit of Abronia lanceolata ......-.-...---------------------------- 326 
67. Fruit of Abronia mellifera .......-...------------------2----------- 326 
