Plants perennial; loosely cespitose, rhizomatous and stoloniferous. Culms 30-90 cm, erect or geniculate at the base. Sheaths open; auricles absent; abaxial ligules present, composed of a line of hairs across the collar; adaxial ligules membranous and sparsely ciliate, sometimes lacerate, cilia subequal to the base; blades flat, linear-lanceolate, resupinate, in living plants the glaucous-green adaxial surface facing downwards and the bright green abaxial surface facing upwards. Panicles not plumose. Spikelets pedicellate, somewhat laterally compressed, with 5-10 florets; rachilla internodes conspicuously pilose; disarticulation at the base of the rachilla segment and below each spikelet. Glumes unequal, lanceolate, unawned; calluses 1.5-2 mm, strigose, hairs 1-1.5 mm; lemmas chartaceous, 3-veined, margins with papillose-based hairs near the base, apices inconspicuously bidentate, awned from between the teeth; awns 3-5 mm, straight; paleas 2-keeled. Caryopses glabrous. x = 10. Name from Hakone, a city on the island of Honshu, Japan, and the Greek chloa, grass.

Hakonechloa is a monotypic genus, endemic to Japan, but grown as an ornamental in the Flora region. The resupination of the blades is not evident on herbarium specimens.

1.   Hakonechloa macra (Munro) Makino
Japanese Forest Grass

Rhizomes and stolons covered with pale, coriaceous scales. Culms 30-90 cm tall, 1-1.5 mm thick, glabrous. Adaxial ligules 0.2-0.3 mm; blades 8-25 cm long, 0.4-1.2 cm wide, glabrous, abaxial surfaces green, adaxial surfaces often paler, turning orange-bronze in the fall. Panicles 6-12 cm long, 5-7 cm wide, open, nodding, with 15-30 spikelets; branches paired, somewhat stiff, scabrous. Spikelets 1-2 cm, yellowish-green, with 5-10 florets. Glumes broadly lanceolate; lower glumes 3-4 mm, 1-3-veined; upper glumes 3.8-5 mm, 3-veined; calluses 1.5-2 mm, strigose, hairs 1-1.5 mm; lemmas 6-7 mm long, 1.8-2.2 mm wide, chartaceous, 3-veined, margins sparsely pilose with long papillose-based hairs near the base, awned; awns 3-5 mm; anthers 2-3 mm. Caryopses about 2 mm. 2n = 50.

In Japan, Hakonechloa macra grows on rocks along rivers. Although rhizomatous, it is not an invasive species and is recommended for mass planting. Three forms are cultivated: forma alboaurea Makino ex Ohwi, with white- and yellow-striped leaves; forma albovariegata Makino ex Ohwi, with white-striped leaves; and forma aureola Makino ex Ohwi, with yellow leaves having narrow green stripes. This last form is the one most commonly available in the Flora region.