242 BARTRAM: BOTANIZING IN SOUTHERN ARIZONA 
CHAETOCBHLOA MACHROSTACHYA (H. B. K.) Scribn. & Merr. Rare on 
talus aN at Robles Pas 
CHAETOCHLOA virivIs (L.) Scribn. Introduced in fields and waste places. 
ARISTIDA ADSCENSIONIS L. Frequent on hillsides in the Tucson Mount- 
ains. 
sansa Wricuti Nash. Uncommon on dry slopes in the Tucson 
Mountain 
ArIsTIDA BROoMoIDES H. B. K. Common in the foothills. Spikelets 
developing through the winter. 
ARISTIDA DIVERGENS Vasey. Dry slopes in the mouth of Sabino Canyon. 
Muu RGIA DUMOSA Scribn. A unique species ee to ledges 
along ie frail in Sabino Canyon at about 3000 feet eleva 
MUHLENBERGIA MICROSPERMA (D C.) Kunth. Rare in oe oS foothills. 
MUHLENBERGIA PoRTERI Scribn. Common in the shelter of shrubs 
on the gravel plains. 
EPICAMPES RINGENS Benth. Slopes in the mouth of Sabino Canyon. 
OUTELOUA FILIFORMIS (Fourn.) Griffiths. Flowering plants collected 
in Sabino Canyon on Janua d 
BovuTELovuA RoTHROCKII Vasey. The dark brown spikelets persist 
well mee the winter. 
LOUA Parryi (Fourn.) Griffiths. This and the preceding species 
are siisndant near Robles Pass. 
TRICHLORIS FASCICULATA Fourn. Roadsides south of Tucson. 
DASYOCHLOA PULCHELLA (H. B. K.) Willd. Generally distributed over 
the plains. 
Ko LERIA CRISTATA so Pers. Along streams in the foothills of the 
Santa Catalina Mountai 
ERAGROSTIS MEGASTACHYA (Koel.) Link. A weed of waste places. 
Poa BIGELOVII Vasey & Scribn. 
Rocks. 
CYPERUS CYRTOLEPIS Torr. & Hook. Edge of stream east of Pima 
Canyon. 
Juncus NODOSUS L. Edge of stream in Pima Canyon. 
Yucca ELATA te Single plants scattered over the plains but 
nowhere abun 
Confined to damp ledges near Picture 
Yucca paccata Torr. Thickets in the mouth of Sabino Canyon. Ap- 
parently washed down from the higher levels. 
NOLINA MICROCARPA S. Wats. With the preceding. 
DASYLIRION WHEELERI S. Wats. On dry ledges in the foothills. 
DIPTEROSTEMON PAUCIFLORUS (Torr.) Rydb. Sparingly in flower along 
an arroyo near Picture Rocks. 
AGAVE Parryi Engelm. On dry ledges in the mouth of Sabino canyon. 
