Cleistogenes polyphylla Keng ex Keng fil. & L. Liou

The habit is distinctive, with many nodes obscured by the overlapping leaf sheaths, broad, often erect leaf blades, and a contracted inflorescence with the base included in the uppermost sheath. The tubercles on the lower leaf sheaths are often purple colored and obvious. Robust specimens are similar to Cleistogenes hackelii var. nakaii, but that taxon has scaly basal buds, longer internodes with the nodes often exposed, and glabrous leaf sheaths.

This is a good mountain forage grass.

Culms loosely tufted from a knotty base with old sheath remnants, lacking basal scaly buds, erect, slender to moderately stout, 25–90 cm tall, 0.8–1.5 mm in diam., many-noded, sometimes branching. Leaf sheaths longer than internodes, tuberculate-hispid (especially the lower), older lower sheaths with disarticulated blades, glabrescent and spotted with tubercles; leaf blades lanceolate or linear-lanceolate, stiffly erect or becoming divaricate, flat with involute apex, 2–10 × (0.2–)0.3–0.6 cm; ligule ca. 0.5 mm. Panicle contracted, 4–8.5 cm, base included in uppermost sheath; branches glabrous in the axils, simple, lowest branch 2–2.5 cm. Spikelets 8–13 mm, green or purple, florets 4–9; glumes lanceolate or oblong; lower glume 1.5–3.5(–4) mm, 1–3(–5)-veined; upper glume 3–5 mm, 3–5-veined; lemmas lanceolate, lowest 4–5.5 mm, loosely pilose near margins and base, emarginate; awn 0.5–1.8 mm; palea keels scabrid. Anthers ca. 2 mm. Fl. and fr. Jul–Oct.

* Dry mountain slopes, along banks of streams. Hebei, Heilongjiang, Henan, Jilin, Liaoning, Nei Mongol, Shaanxi, Shandong, Shanxi.

Cleistogenes hancei Keng var. jeholensis (Honda) Kitagawa; C. serotina (Linnaeus) Keng var. jeholensis Honda; Kengia hancei (Keng) Packer var. jeholensis (Kitagawa) H. Yu & N. X. Zhao; K. polyphylla (Keng ex P. C. Keng & L. Liu) Packer.