ILLUSTRATIONS. 
Facing page. 
. Parmelia saxatilis (L.) Ach. and P. physodes (L.) Ach.............. 195 
. Parmelia pertusa (Schrank.) Schaer................2022.20-2022--- 196 
. Evernia prunastri (L.) Ach....... 20... 0 cece eee eee cece ee 203 
. Ramalina calicaris (L.) Fr....... 0... cece eee eee 204 
. Ramalina calicaris (L.) Fr. and R. pusilla Prev.................... 204 
. Alectoria jubata (L.) Ach. and Usnea longissima Ach........ weeeeeee 206 
. Usnea cavernosa Tuck.......... 000.0 c cee cece cece eee ceceeeeee 210 
. Placodium elegans (Link) Ach. and P. cerinum (Hoffm.) Hepp..... 213 
. Teloschistes chrysopthalmus (lu.) Th. Fr............2.222-22220-00ee 217 
. Teloschistes polycarpus (Hoffm.) Tuck. and Rinodina sophodes (Ach.) 
Koerb. ..- 2-2... eee cee cece cece cee eeceeeees 218 
. Physcia ciliaris (L.) Ach. and P. stellaris (L.) Nyl.............- 2... © (226 
. Pyxine sorediata (Ach.) Fr......... 00.00.00 eee eee eee eens 230 
. Verrucaria nigrescens viridula (Schrad.) Nyl. and Pyrenula leucoplaca 
(Wallr.) Koerb. 2.22.2... 2.22.0 ccc cece cece cee eecececes 235 
. Dermatocarpon miniatum aquaticum (Weis.) Fink and Staurothele 
umbrina clopima (Wahl.) Tuck................002 22222 e eee e eee ee 243 
. Amphiloma lanuginosum (Hoffm.) Nyl...........2..2..0.20eeee eee 247 
. Coconut palms at Salama, Guatemala....................2.2------ 271 
. Fig. Fig. 2.—Dried cotyledons of coco- 
. Fig. 1—Coconut palms overhanging the surf at high tide, Puerto 
Barrios, Guatemala. Fig. 2.—Coconut palms overhanging the 
sea, Livingston, Guatemala....... wee eee cece eee ee ee 299 
. Peach palms (Gutlielma speciosa) in Costa Rica .............. ..--- 308 
. Peach palm (Guilielma speciosa) with fruit and seed................ 308 
. The coyol palm (Acrocomia vinifera)............2.0- 02.0 cece ee eeee 313 
. Trunk and fruit clusters of the corozo or manaca palm (Attalea 
COMUNE). ...20 cece cece cece eee eee cece eee ee cece cece eee eeeeeees 314 
. Fig. 1.—Germinating coconut. Fig. 2.—Cross section of coconut 
germinating inside the husk....................2.-..002eeeeeeee 327 
. Germination of the corozo palm (Attalea cohune)............2.2+--- 328 
. Germination of the coyol palm (Acrocomia vinifera)........ ---. 328 
. Flowers and fruit of a young coconut palm, Belize, British Hon- 
duras. . 22.2... e cence eeceeeces 330 
. Fruit clusters of a mature coconut palm, Costa Rica............... 330 
. Inflorescence of the coconut palm, with staminate and pistillate 
CO) 330 
. Fig. 1.—Coconut palm at Cajabon, Alta Verapaz, Guatemala. Fig. 
2.—Coconut palm near Palmira, Cauca Valley, Colombia......... 332 
. Coconut palm at Belize, British Honduras.......................-. 333 
. Habitat of Bouteloua spp. in the Tucson Mountains, Arizona. 
68. 
A. Closely grazed Bouteloua region in southern Arizona. B. Habi- 
tat of tall-growing species of Bouteloua in southern Arizona...... 345 
. A. Bouteloua curtipendula (Michx.) Torr. in cultivation. B. Bou- 
teloua gracilis (H. B. K.) Lag. in cultivation.................--. 345 
. A. General view of a good Bouteloua region. B. Spring view of a 
Bouteloua region closely grazed... .-...2...... 020 eeeeeeeeeeeeee 346 
. A. Typical view in a Bouteloua region showing a variety of species. 
B. Bouteloua region with a different soil and different species.... 346 
. A. Large native crop of Bouteloua gracilis (H. B. K.) Lag. B. Bou- 
teloua gracilis on the Mexican border of Arizona............-..--- 377 
. A. Large plant of Bouteloua parryi (Fourn.) Griffiths. B. Bou- 
teloua barbata Lag........... oo en erenecercrerencsecceeescescenes 382 
