 In warm desert , mesquite ( Prosopis spp . ) and creosotebush ( Larrea tridentata ) are principal browse species . Broom snakeweed ( Gutierrezia sarothrae ) and Yucca spp. are also used . In honey mesquite ( Prosopis glandulosa var. glandulosa ) communities in New Mexico , the overall black @-@ tailed jackrabbit diet was 47 % shrubs , 22 % grasses , and 31 % forbs . Black grama ( Bouteloua spp . ) , dropseed ( Sporobolus spp . ) , fluffgrass ( Erioneuron pulchellum ) , and threeawns ( Aristida spp . ) are the most commonly grazed grasses . Leather croton ( Croton pottsii ) , silverleaf nightshade ( Solanum elaeagnifolium ) , desert marigold ( Baileya multiradiata ) , wooly paperflower ( Psilostrophe tagetina ) , and globemallow ( Sphaeralcea spp . ) are important forbs , although many forb species are grazed . Opuntia spp . , saguaro ( Carnegiea gigantea ) , and other cacti are used throughout the year , but are especially important in dry seasons as a source of moisture . 
