耳基冷水花 er ji leng shui hua

Herbs perennial, stoloniferous, glabrous, dioecious or monoecious. Stems gray green when dry, simple or branched, to 100 cm tall, succulent, with galls on mid portion of internodes. glabrous or puberulent distally, densely covered with cystoliths, Stipules persistent, interpetiolar, triangular, connate at base, ca. 1 mm, membranous; petiole unequal in length, longer one 2.5-12 cm, shorter one 0-4 cm; leaf blade abaxially pale green, adaxially dark green, obliquely oblong-ovate or ovate-lanceolate, unequal in size, 5-15 × 2.5-8.5 cm, submembranous, 3-veined, lateral veins many, transverse, base auriculate, sometimes subcordate, margin coarsely, shallowly crenate-serrate, apex acuminate, acumen serrulate. Inflorescences solitary; male inflorescence a cymose panicle, longer than petioles; female cymose panicles 3-5 cm. Male flowers sessile, in bud ca. 1.2 mm; perianth lobes 4, obovate or obovate-oblong; stamens 4; rudimentary ovary small, subulate. Female flowers subsessile, in bud ca. 0.6 mm; perianth lobes connate at base, unequal, abaxial lobe cymbiform, longer, subapically corniculate; staminodes 3, inconspicuous, scale-like, oblong. Achene dark brownish, ovoid, ca. 1.2 mm, compressed, reticulate. Fl. Sep-Oct, fr. Oct-Jan.

* Shaded wet places along streams, near streams; 2400-2800 m. SE Xizang, NW Yunnan.

This species is similar to Pilea martini, but that species has oblong stipules, a rounded leaf base, and an oblique, smooth achene.