Panicum amarum is a perennial C4 grass (Aliscioni et al.), stems 1-2 m tall, solitary or in small clusters, colonial from deep rhizomes, plants very waxy blue-green, ligule of dense white hairs up to about 0.3 cm long.
Leaves alternate, elongate, to 50 cm long, 1 cm wide.
Flowers dry, papery, spikelets 1-flowered, 0.5-0.7 cm, tip tapered; inflorescence 15-40 cm long, sparsely flowered, rather contracted, 1-2 short branches per node, secondary and tertiary branching common; blooming and fruiting July-Sept.
Fruit dry, 1-seeded grain.
Wetland status: FACU-.
Frequency in NYC: Rare: (NYS S3, U).
Habitat: Sandy coastal areas, dunes, soil pH 5-7.5, tolerant of fire, drought, moderately tolerant of salt, intolerant of shade (USDA, NRCS 2010).
Notes: Planted in grassland restorations.