丝茎萹蓄 si jing bian xu

Herbs annual. Stems erect, usually purple-red, 5-10 cm tall, slender, 3-5 mm in diam., glabrous, internodes 1-1.5 cm. Petiole short; leaf blade spreading or curved, linear or subulate, 7-15 × 0.5-1 mm, both surfaces with conspicuous midvein, base articulate, apex mucronulate; ocrea silvery, narrowly ovate, thinly membranous, pellucid, base connate, margin entire or slightly denticulate, apex acute. Flower solitary, axillary. Pedicel short. Perianth white, 5-cleft to 3/4, membranous; tepals elliptic, 2-3 mm, apex obtuse. Stamens 5, sometimes fertile ones 2 or 3; filaments dilated at base; anthers black. Styles 2, very short; stigmas capitate. Achenes equaling or slightly exceeding persistent perianth, shiny, ovoid, biconvex, ca. 2 mm, smooth, apex acute. Fl. Jun-Jul, fr. Jul-Aug.

In sand at riversides, dry mountain slopes; 300-500 m. Xinjiang [Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan; SW Asia].