Zanthoxylum parvum (Rutaceae), a New Species from Trans-Pecos Texas

ZANTHOXYLUM parvum Shinners, sp. nov. ex affinitate Z. americani. Frutex ad 1.5 m. altus aculeis rectis vel arcuatis 5-12 mm. longis ad nodos armatus. Foliola 7-9 late elliptico- vel ovato-lanceolata obtusa crenulata in ambitu pilosula 6-11 mm. longa. Inflorescentia quasi umbellata sessilis ante folia maturans. Flores 2-12 foeminei pedicellis 2-4 mm. longis parce pilosulis. Sepala desunt. Petala 4 ellip-tico- vel ovato-oblonga 1.6-1.9 mm. longa viridia apice rufobarbata. Ovarium crasso-stipitatum. Carpella 2-4 connata breviter tomentosa; styli sat tenues prius contorti quasi connati demum liberi, stigmatibus brevibus subclavatis. Flores mares fructusque ignoti. HOLOTYPE: Rocky (igneous) hills above Limpia Creek near Wild Rose Pass, about 15 miles N.E. of Ft. Davis, Jeff Davis Co., Texas, Rogers Mc Vaugh 7890, 10 April 1947 (in Herb. Southern Methodist University). High slopes under north-facing cliffs, branch canyon to east, just above pass. Shrub 1.5 m. high. The specimen is in flower, with very young leaves