12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I4O 



S Grounds of a private residence, Lubbock, Tex. 



SL Serpent Lake, above Tres Ritos, N. Mex. 



TR Tres Ritos, N. Mex. 



TT Texas Technological College campus, Lubbock. 



W Washington, D. C. 



XS Texas Agricultural Experiment Substation, Lubbock. 



Y University of Arizona Agricultural Experiment Station, Yuma. 



SPECIES SYMBOLS 



A Hibiscus syriacus, shrubalthea, rose-of-Sharon. 



Al Alnus temdjolia, thinleaf alder. 



Ap Malus syhestris (Pyrus malus), apple. 



As Fraxinus sp., ash. 



Asp Populus tremuloides, quaking aspen. 



C Cupressus arizonica, Arizona cypress. 



Qa Sapindiis drummondii, wild chinaberry, soapberry. 



Ch Primus sp., black cherry. 



Ct Citrus maxima (C grandis), grapefruit. 



Cw Populus sp., Cottonwood. 



E Ulmus pumila, Siberian elm (often miscalled Chinese elm). 



F Abies lasiocarpa var. arizonica, corkbark fir; A. concolor, white fir. 



Fl Pinus flexilis, limber pine. 



G Grossularia sp., gooseberry. 



J Juniperus flaccida, drooping juniper ; /. pachyphloea, alligator juniper ; 



/. sibirica, dwarf juniper; /. virginiana, red cedar; Juniperus sp., 



red cedar. 



Jf Pinus jeffreyi, Jeffrey pine. 



L Gleditsia triacanthos, honeylocust. 



M Acer saccharinum, silver maple. 



O Elaeagnus angustifolia, Russian olive, oleaster. 



P Pinus aristata, foxtail pine, bristlecone pine; P. cembroides, Mexican 



pitiion ; P. pofiderosa, ponderosa pine ; Pinus sp. 



Pe Primus persica (Amygdalus persica), peach. 



PI Primus sp., plum. 



S Platamis occidentalis, American sycamore. 



Sp Picea engelmunnii, Engelmann spruce. 



T Pinus taeda, loblolly pine. 



Th Thuja sp., arborvitae. 



V Vitex agnus-castus, vitex, chaste or hemp tree. 

 W Salix spp., willow. 



The complete symbol used to designate each single tree or shrub 

 was made by combining a locality symbol with a species symbol. For 

 instance, a pine from the campus of Texas Technological College was 

 designated TTP, for Texas Technological pine, and a wild chinaberry 

 from Coopers Canyon was, after a similar fashion, labeled CCCb. 



Information having to do with the trees used in our work is given 

 in table 4 and includes complete symbol, specific name, height, diam- 

 eter, amount of competition, and certain additional ecological data. 

 Diameter is given under symbol D.b.h., diameter breast high. 



