T: Japan, circa Simoda, P.A.L.Savatier 1354; holo: P, iso [fragment]: W, LE.
Perennials, (15–) 30–50 (–60) cm tall; rhizome horizontal, creeping, ±short-noded, c. 2 mm thick; stem rigid, erect, c. 1.5–2.5 mm thick. Cataphyll usually 0–1; sub-basal leaves 1–2. Cauline leaves 2–3, unitubular, perfectly septate, usually long (to c. 20 cm), often reaching inflorescence; auricles subobtuse, oblong, scarious, usually 1–2.5 mm long. Lower bract leaf-like, usually shorter than the inflorescence, rarely to 5 cm and then often exceeding inflorescence. Inflorescence rich, often dense to subdense; main branches 3–8, erect to suberect; secondary or all branches often ±abbreviated, of many ±obconical, usually 3–10-flowered heads. Tepals ±equal or inner ones slightly longer, lanceolate, usually distinctly 3-veined, greenish, later stramineous-brown, acute to mucronate, c. 2.2–3.0 mm long; margins narrow, membranous. Stamens (3–) 6; anthers 0.3–0.5 mm long; filaments 0.9–1.4 mm long; style 0.2–0.3 mm long; stigmas c. 1.0–1.5 mm long. Capsule oblong-ovoid, ±acutely trigonous, unilocular, c. 2.7–3.1 mm long, subabruptly narrowing into a 0.2–0.3 mm rostrum, castaneous-brown to pale brown, usually slightly (rarely distinctly) exceeding perianth. Seeds ovoid-ellipsoid, apiculate, c. 0.5 × 0.2–0.3 mm, pale brown, longitudinally c. 20-striate, finely reticulate; appendages absent.