10. Hemerocallis esculenta Koidzumi, Bot. Mag. (Tokyo). 39: 28. 1925.
北萱草 bei xuan cao
Hemerocallis dumortieri C. Morren var. esculenta (Koidzumi) Kitagawa; H. middendorffii Trautvetter & C. A. Meyer var. esculenta (Koidzumi) Ohwi.
Roots slightly fleshy, usually with a fusiform, swollen, tuberous part near tip 2--4 × ca. 1 cm. Leaves linear, 40--80 × (0.6--)1--1.8 cm, soft. Scape erect, generally slightly shorter than leaves, hollow; sterile bract absent. Inflorescences short, 0.2--6 cm, usually with 1 double helicoidal cyme; cyme somewhat densely 1--3(or 4)-flowered, basal pedicel sometimes concaulescent; bracts ovate-lanceolate, 1--2(--4) × 0.8--1.5 cm. Pedicel 3--6 mm. Flowers slightly fragrant. Perianth golden yellow; tube 1.5--2.5 cm; segments spreading, 5--6.5 cm, inner ones slightly wider than outer, 1--2 cm wide. Filaments ca. 5 cm; anthers purplish black, ca. 6 mm. Capsule subellipsoid, 2--2.5 × 1.2--1.4 cm. Fl. May--Jun. 2 n = 22*.
Forests, forest margins, grassy slopes, stony places, roadsides; 500--2500 m. Gansu, Hebei, Henan, Hubei, Liaoning, Ningxia, Shaanxi, Shandong, Shanxi [Japan, Russia (Sakhalin)].