R0SE — MEXICAN AND CENTRAL AMERICAN PLANTS. 293 



The hills about Nogales are low with rounded summits and bear 

 a very scanty desert vegetation. Seven species of Cactaceae belong- 

 ing to the genera Mamillaria, Opuntia, and Echinocactus were col- 

 lected. The rare Yucca brevifolia Engelm., was collected in full 

 flower (pi. 48). This was taken not far from the type locality of the 

 species, which was first collected by A. Schott some time in the 

 fifties. Only leaves were obtained by Schott and flowers have never 

 been collected until now. These are borne in large, erect, compact 

 panicles, are white and hanging, and instead of being small as they 

 were supposed to be, are very large. Linum puberulum (Engelm.) 

 Heller, was common, while a curious Rhus, perhaps Toxicodendron 

 phaseoloides Greene, grew attached to the perpendicular side of a 

 cliff. A Nolina was common, but was not in flower or fruit and no 

 specimens were taken. Cowania stanshuriana, a characteristic shrub 

 was in full flower and herbarium specimens and a photograph were 

 secured (pi. 49). Calochortus Jcennedyi was not uncommon. 



On May 16, accompanied by Mr. C. R. Orcutt, I drove from San 

 Diego to Initial Monument on the boundary line between Lower 

 California and the State of California. As Mr. Orcutt is very familiar 

 with all this region it was an unusual privilege to have him point 

 out the many interesting plants, not a few of which have their type 

 localities at this station. Among the Cactaceae which were of inter- 

 est to me were Bergerocactus emoryi, Echinocactus limetus, Opuntia 

 serpentina, 0. prolifera, and Mamillaria dioica. 



ITINERARY. 

 1908 - , . . . ™.-i i. 



March 29 30 Juarez and vicinity, Chihuahua. 



. -i i 9 Minaca, Chihuahua. 



9' o Cusihuiriachic, Chihuahua. 



3 ' 4 ' * Chihuahua City, Chihuahua. 



' 4 " Santa Eulalia Mountains, Chihuahua. 



5_g Juarez and vicinity, Chihuahua. 



29 3Q Nogales and vicinity, Sonora. 



May ' 14 ' Initial Monument, International Boundary, Lower California. 



COMMELINACEAE. 

 SETCREASEA AN OLDER NAME THAN NEOTRELEASEA. 



A new genus Treleasea was established by the writer in 1899, but 

 in 1903 he changed the name to Neotreleasea on account of an earlier 

 genus Treleasea of fungi which had been overlooked. In the mean- 

 time, however, Schumann and Sydow had renamed it Setcreasea. a 



Since my publication of this genus as Treleasea I have repeatedly 

 studied it in the herbarium and greenhouse and in the field in Mexico. 

 The generic characteristics assigned to it are perfectly satisfactory. 



oSetcreasea Schum. & Sydow, Just's Bot. Jahresb. 27 1 :452. 1901. 



