15. Polygonum acerosum Ledebour ex Meisner in Candolle, Prodr. 14(1): 92. 1856.
松叶萹蓄 song ye bian xu
Herbs annual. Stems ascending, often pinkish, 15-25 cm tall, papillate, branched from base. Leaves sessile; leaf blade green, linear or linear-lanceolate, 8-20 × 2-3 mm, nearly fleshy, abaxially midvein prominent, adaxially midvein conspicuous, lateral veins inconspicuous on both surfaces, base narrowly cuneate, margin entire, slightly revolute, apex acute, with mucro; ocrea silvery, ovate-lanceolate, 4-5 mm, membranous, base connate, apex lacerate. Flower solitary, axillary. Pedicel very short, articulate at apex. Perianth 5-cleft to 1/2, herbaceous, minutely papillate, margin white; tepals elliptic, 1-1.5 mm. Stamens 7 or 8. Styles 3, very short. Achenes included in persistent perianth, dark brown, slightly shiny, ovoid, trigonous, 2-2.5 mm, puncticulate. Fl. May-Jun, fr. Jun-Jul.
Riverbanks, moist valleys; 500-1500 m. Xinjiang [Afghanistan, Kazakhstan, Kyrgyzstan, Tajikistan].