Japan Flora: Rhizomes slender, long-creeping; stems erect, about 40 cm. long, glabrous; leaves rather loose, lanceolate or oblong-lanceolate, 5-8 cm. long, 1-2 cm. wide, obtuse, glabrous, the midrib rather thick and slightly raised beneath, the verticillate leaves rather small, the involucral leaves orbicular- or cordate-triangular, 6-15 mm. long, truncate at base; inflorescence loose, the glands of the involucres lunate-reniform, both ends extended and obtuse, about 2.5 mm. wide; capsules smooth. May.