Pinus edulis Engelm. and Juniperus spp. are dominant, 
while Bouteloua hirsuta Lag., Bouteloua curtipendula 
(Michx.) Torr. and other grasses form an almost contin- 
uous ground cover with scattered herbaceous plants and 
‘acti (mainly Opuntia spp.). In one canyon near Bat 
Cave there are several trees of Pinus ponderosa Doug}. 
ex P. Laws. No other occurrence of ponderosa pine was 
seen near the site. 
During the dry season the vegetation has a distinctly 
xerophytic aspect emphasized by the scattered plants of 
Opuntia and Mammillaria. Only the heliotrope on the 
plains and the shrubs on the terraces remain green. The 
dark green of the pifon and juniper contrasts with the 
brown ground cover. 
With the advent of the summer rains in July and 
August, many short-lived herbs appear over the plain 
and hills making the entire area green. Most of the 
vegetation blooms during this period. Heavy rains in 
the hills and mountains usually fill the canyon beds with 
temporary streams for several hours each day, and stand- 
ing pools form on the playa. 
EXCAVATION 
The vegetal material recovered from Bat Cave was 
collected during the course of excavation for archeologi- 
cal remains. Measured areas were carefully dug by hand 
troweling in twelve inch levels from the top of the de- 
posit. The material of botanical interest was removed 
and packaged. These arbitrary strata have no relation to 
any archeological strata which may exist in the Bat 
Cave deposit. Many cubic yards of material were re- 
moved so that a fair sampling of the entire deposit was 
obtained. Vegetal artifacts, to be described later by Mr. 
Dick, were packaged separately. Aside from the maize 
remains previously studied, no attempt was made in the 
[ 159 | 
