西南萱草 xi nan xuan cao

Plants 40--70 cm tall. Roots slightly fleshy, with large, globose, swollen, tuberous part near tip 1.5--2.5 × 3.5--4.5 cm. Leaves linear, 30--70 × 1--2 cm, rather stout, base surrounded by fibrous remains of older leaves, apex obtuse. Scape slender, nearly as long as leaves, hollow; main axis indistinct; sterile bracts absent. Inflorescence branches 4--6, each with 1 double helicoidal cyme dichotomously or trichotomously branched; cymes 2--4-flowered; bracts lanceolate, 0.5--2.5 cm × 3--10 mm. Pedicel 1.5--3 mm. Flowers rather small, opening during day. Perianth orange or golden yellow; tube short, ca. 1 cm; segments 5--9 cm, outer ones ca. 5 mm wide, inner ones slightly wider than outer, 1.2--1.5 cm wide. Filaments 3--4.5 cm; anthers yellow or slightly blackish, ca. 7 mm. Capsule ellipsoid, ca. 3.8 × 1.5--2 cm. Fl. May--Jun. 2 n = 22*.

* Forests, grassy slopes, limestone cliffs; 2300--3200 m. SW Sichuan, NW Yunnan.