**NEW SPECIES OF OPUNTIA. BY DAVID GRIFFITHS.** *Opuntia aciculata* **sp. nov.** A low, hemispherical shrub, 1 m tall, with a branch spread of 1 to 2 m; erect or with main arms ascending or even resting on the edge, and secondary branches erect from them; joints ovate to obovate, mostly pointed at both ends, 15 by 20 cm, though older joints on our specimens measure only 12 by 17 cm, dark green with some bloom; leaves circular in cross-section, subulate, cuspidate, 7 mm long, gradually recurving with age; areoles subcircular, varying from 4 to 6 mm in diameter, with conspicuous brown wool protruding 1 mm or more above the joint surface, spaced about 2 cm apart on the sides of the joints; glochids bright brown, conspicuous and formidable, 5 to 7 mm long, with lighter-colored tips, nearly uniformly scattered throughout the areoles, the tuft tips measuring 10 to 12 mm in spread; spines very few, only occasional on occasional areoles, brown, sloping downward, 1 to 2 cm long; flowers yellow with a greenish center, 9 cm in diameter, filaments greenish-tinged, style white, stigma dark green, subglobose, with 8 to 10 lobes; fruit pyriform, deep purplish-red throughout, developing a slight bloom until early maturity. The type specimen is preserved under my inventory number 10,300, collected near Laredo, Texas, on June 26, 1911. The description was based on cultivated plants grown in Chico, California, on May 21, 1914. The distinguishing characteristics of the species are the prominent, brown, abundant glochids, pointed joints, and remarkably few spines. It differs from *Opuntia tardospina* in being smaller in overall stature, almost spineless even at maturity, and in having differently shaped joints.