Arachnothryx costaricensis (Standl.) Borhidi

Rondeletia costaricensis Standley, sp. nov
Branches slender, grayish, glabrous; stipules foliaceous, the blades suborbicular, 5 mm. long, green, glabrous; leaves opposite, the petioles slender, 7-10 mm. long, the blades elliptic or oval-elliptic, 13.5-18.5 cm. long, 6.3-8 cm. wide, acute at the base, acuminate at the apex, membranaceous, glabrous, green above, pale beneath, the venation prominent, the lateral veins slender, 6-8 on each side, subarcuate; inflorescence terminal, cymose-paniculate, rather few-flowered, the peduncle slender, 6.5 cm. long, the rachis minutely pilose, the pedicels 1-3 mm. long; hypanthium less than 1 mm. long, minutely appressed-pilose ; calyx-lobes 4, narrowly triangular, acute, shorter than the hypanthium, erect; corolla minutely appressed-pilose outside, the tube slender, 9 mm. long, the 4 lobes oval, 3 mm. long.
Type collected near Buena Vista, Costa Rica, altitude 900 meters, April, 1903, H. Pittier 16696 (U. S. Nat. Herb. no. 764141).