![Transcription Center logo](/themes/custom/tc_theme/assets/image/logo.png)
This transcription has been completed. Contact us with corrections.
[[underlined]]Acacia constricta[[/underlined]]- Common from Benson to Tucson. Not found at Casa Grande or west of there. [[underlined]]Mimosa roemeriana?[[/underlined]] - This catsclaw was found at Lordsburg & Duncan New Mex., and at Benson, Tucson, Casa Grande & west to the Mohawk Mts., Arizona, but no farther. [[underlined]]Fouquiera spinosa[[/underlined]]- Common at Lordsburg N.M., at Benson, Ariz, and westward to Tucson, Casa Grande - all the way to Yuma & beyond on mesas & stoney slopes. [[underlined]]Chilopsis saligva [[/underlined]]- Common along the Rillita creek near Tucson, but not found west of there. Other plants that range west to Tucson & no farther are:- Opuntia englemani "[[ditto for Opuntia]]s (mainly spineless) "[[ditto for Opuntia]](brown spined) "[[ditto for Opuntia]] leptricaulis Agave [[space]] fig Yucca palmeri? "[[ditto for Yucca]] radiosa Koeberlinia spinosa Ephedra trifurcata? [[end page]] [[start page]] There seems to be a marked break in range of species just west of Tucson but it needs careful working out with camp outfit. It is evidently the change from Lower Sonoran to arid subtropical - or the "lower division" of lower sonoran. The marginal distribution of Giant cactus and palms (Washingtonia) around the sides of valleys would suggest that a hotter belt than is found in the bottom of the valleys. A series of experiments would show whether this is the case and whether the giant cactus belt is frostless.