43. Pilea plataniflora C. H. Wright, J. Linn. Soc., Bot. 26: 477. 1899.
石筋草 shi jin cao
Pilea blinii H. Léveillé; P. dielsiana Handel-Mazzetti; P. kankaoensis Hayata; P. langsonensis Gagnepain; P. minutepilosa Hayata; P. petelotii Gagnepain; P. taitoensis Hayata.
Herbs perennial, long stoloniferous, glabrous, dioecious or monoecious. Stems green blue when dry, 10-70 cm tall, woody at base, succulent distally, swollen between nodes. Stipules gradually deciduous, triangular, 1-2 mm, membranous; petiole often unequal in length, 0.5-7 cm; leaf blade dark green or green blue, ovate, lanceolate, or obovate-oblong, asymmetric, unequal or equal in size, 1-15 × 0.6-5 cm, thinly papery or submembranous, 3(or 5)-veined, lateral veins many, irregularly reticulate, external secondary veins anastomosing by margin, sometimes inconspicuous, cystoliths finely fusiform, conspicuous adaxially, base obliquely rounded or subcordate, sometimes cuneate, margin entire or sometimes undulate, apex shortly or long caudate-acuminate. Inflorescences solitary; male inflorescence a cymose panicle or racemelike, often longer than leaves; female cymes as long as or shorter than leaves, pedunculate. Male flower subsessile, in bud ca. 1.5 mm; perianth lobes 4; stamens 4; rudimentary ovary minute. Female flowers subsessile, ca. 0.5 mm; perianth lobes connate at base, subequal, abaxial lobe larger, subapically corniculate; staminodes 3, conspicuous, scale-like, rhombic-oblong. Achene brownish, ovoid, ca. 0.6 mm, compressed, slightly oblique at apex, verrucose. Fl. (Apr-)Jun-Sep, fr. Jul-Oct.
Broad-leaved forests, semishaded wet places, karst limestone, near streams; 200-2400 m. SE Gansu, W Guangxi, Hainan, Hubei, S Shaanxi, Sichuan, Taiwan, Yunnan [Thailand, N Vietnam].
This species is widespread and exhibits great variability in plant height, leaf size and shape, and inflorescence length. It has a disjunct distribution, occuring in SW mainland China and Taiwan. Many names not included here have been treated as synonyms of this species.