Key, synonymy, descriptions, and information on distribution and ecology are given for the two species recognized. These are Savia phyllanthoides (Nutt.) Pax & K. Hoffm. and S. arida, new species, with type from Brewster County, Texas. We provide key, synonymy, detailed descriptions, and information on distribution and ecology for the two species of the primarily tropical genus Savia which occur in extreme western Texas. We are indebted to Dr. Grady L. Webster of Purdue University for going over the manuscript and providing valuable comments and suggestions. Hannah Croasdale of Dartmouth College provided the Latin diagnosis. We are grateful to the personnel of the several herbaria which loaned specimens for study; these herbaria are abbreviated in the citations according to Lanjouw and Stafleu (1956). Savia Willd., Sp. P1. 4: 771, 1806. KEY TO THE SPECIES OF SAVIA IN THE TRANS-PECOS AND ADJACENT COUNTIES Leafy twigs 10-30 (-55) cm long, usually weakly arcuate; leaf-blades mostly more than 10 mm long; staminate pedicels 6-12 mm long; pistillate pedicels 8-22 mm long 1. S. phyllanthoides (Nutt.) Pax & K. Hoffm. Leafy twigs 5-10 cm long, grayish white, rigidly straight; leaf-blades mostly less than 10 mm long; staminate pedicles 2-3.2 mm long, pistillate pedicels 3-4 mm long. 2. S. arida Warnock & Johnston 1. SAVIA PHYLLANTHOIDES (Nutt.) Pax & K. Hoffm., Das Pflanzenr. IV 147 XV (Heft 81): 184, 1922. Based on Lepidanthus phyllanthoides Nutt., Trans. Amer. Phil. Soc. n.s. 5: 175, 1835 [not 1837]. Windingstair Mountains, western LeFlore County, eastern Oklahoma, just north of present town of Talihina, Nuttall, May 18, 1819 (BM?, PH?). Nuttall says in his journals (ex Geiser, 1956) that at this place he found a "shrubby plant allied to Phyllanthus." Andrachne phyllanthoides (Nutt.) Coulter, Contr. U. S. Natl. Herb. 2: 396, 1894 [comb.