The genus Stegnosperma (Phytolaccaceae) has been considered monotypic since Walter's treatment for Engler's 'Pflanzenreich'1. However, an examination of specimens in the major North American herbaria shows the inclusive species S. halimifolium Benth. of Walter to be rather heterogeneous. Actually, three species exist, two of which have been described and published, the third noted by S. Watson on an herbarium label but never published. A description of the third species is provided here and is named for Dr. Watson. STEGNOSPERMA Watsonii D. J. Rogers, n. sp. Frutices aut scandentes aut crassi patulique 1-5 m. alti, 1-5 m. diam., cortice griseo vel rufo-brunneo. Folia anguste spathulata vel elliptica emarginata vel rotunda vel acuta 1.0-3.5 cm. longa 0.5-2.5 cm. lata, petiolo 0.1-0.3 cm. longo. Inflorescentia cymulis axillaribus aut terminalibus 1-8-floris; calycis lobis ellipticis vel ovatis 0.3-0.7 cm. longis 0.2-0.4 cm. latis; petalis ovatis rotundatis basi abrupte constrictis; fructu capsula 5loculata plerumque in 5 valvis dehiscente; seminibus plerumque 5 aliquando 4 ovoideis vel ellipsoideis circa 0.3 cm. longis 0.2-0.3 cm. latis, cicatrice funiculari laterali, raphe in jugum dorsalem, testa levi fulgenti rufo-brunneo. Sprawling vine or coarse spreading shrub, 1-5 m. tall, 1-5 m. diameter spread; bark gray to reddish brown. Leaves narrowly spathulate to elliptic, emarginate to rounded to acute, 1.0-3.5 cm. long, 0.5-2.5 cm. wide, petiole 0.1-0.3 cm. long. Inflorescence of axillary or terminal 1to 8-flowered cymules; calyx lobes elliptic to ovate, 0.3-0.7 cm. long, 0.2-0.4 cm. wide; petals ovate, rounded, abruptly constricted at base; fruit a 5-celled capsule, usually dehiscing by 5 valves; seeds usually 5, occasionally 4, ovoid to ellipsoid, about 0.3 cm. long, 0.2-0.3 cm. wide, funicular scar lateral, raphe on a dorsal ridge, testa smooth, shiny, reddish brown.