12. Pilea longicaulis Handel-Mazzetti, Symb. Sin. 7: 127. 1929.
长茎冷水花 chang jing leng shui hua
Subshrubs or perennial herbs glabrous, dioecious. Stems light green when dry, terete, 50-80 cm; stems, stipules, petioles, and leaves densely covered with cystoliths. Stipules deciduous, green, oblong, 7-9 mm, papery, longitudinally 2-ribbed; petiole subequal in length, 1-3 cm; leaf blade pale green, elliptic-lanceolate, elliptic, rarely ovate, subequal in size, 6-15 × 3-6 cm, ± succulent, but thinly papery when dry, 3-veined, lateral veins 10 each side, transverse, inconspicuous on both surfaces, external secondary veins indistinctly anastomosing by margin, both surfaces lustrous, base obtuse, broadly cuneate, rounded, or subcordate, margin entire or erose, rarely serrate distally, apex acuminate or shortly caudate-acuminate. Inflorescences in pairs; male inflorescence a dichotomously branched cymose panicle or cymose raceme, or compacted into capitulum, 1-2(-5) cm. Male flowers purplish or yellow, pedicellate, in bud obovoid, ca. 1.5 mm; perianth lobes 4, elliptic, connate 1/2 of length, subapically corniculate; stamens 4; rudimentary ovary conic. Female flowers subsessile; perianth lobes elliptic, persistent perianth 1/3 as long as achene; staminodes oblong. Achene ellipsoid-ovoid, ca. 1.5 mm, compressed, with a purplish ring on both surfaces. Fl. Jan-Feb, fr. Mar-May.
Shaded wet places in forests often in limestone mountains; 400-1500 m. W Guangxi, Guizhou, Sichuan [Laos, N Vietnam].