Annual herb, tufted 8 cm - 1 m tall Leaves: often crowded at the base. Sheaths usually longer than internodes, rounded, hairy (hairs to 5 mm long and bumpy-based). Ligules 0.5 - 1.5 mm long, membranous. Blades spreading, greenish or purplish, 3 - 30 cm long, 5 - 12 mm wide, linear with a nearly heart-shaped to truncate (cut straight across) base and pointed tip, flat, parallel-veined, stiff-hairy to sparsely soft-hairy, marginally fringed with hairs at the base. Inflorescence: a branched arrangement of spikelets (panicle), diffuse, 7 - 27 cm long, 4 - 24 cm wide, about one-third as long as the plant, exserted, with spreading primary branches and diverging secondary branches. Secondary branches with one to four spikelets. Fruit: a caryopsis, indehiscent, enclosed within the persistent lemma and palea. Culm: spreading to decumbent, rooting at the lower nodes, branched above, 8 cm - 1 m long, about 1 mm wide, round in cross-section, hairy (hairs bumpy-based). Nodes sparsely to densely soft-hairy. Spikelets: green, 2 - 2.5 mm long, about 0.5 mm wide, lance-shaped to ellipsoid. Glumes: unequal, herbaceous. Lower glumes 0.5 - 1 mm long, less than half as long as spikelets, truncate (cut straight across) to pointed at the apex, three- to four-veined. Upper glumes straight, 1.5 - 2 mm long, pointed at the apex, seven-veined. Lemmas:: Lower lemmas similar to upper glumes, straight, 1.5 - 2 mm long, pointed at the apex, seven- to nine-veined, keeled. Upper lemmas shiny, with rolled-up margins on the upper surface. Paleas:: Lower paleas absent. Upper paleas longitudinally lined. Florets:: Lower florets sterile. Upper florets bisexual, straw-colored, about 1.5 mm long, under 0.5 mm wide, about half as wide as long, pointed and minutely bumpy at the apex. Anthers three. Stigmas red.

Similar species: No information at this time.

Flowering: September

Habitat and ecology: A rare weed of the Chicago Region. It is found in dry ruderal areas.

Occurence in the Chicago region: native

Etymology: Panicum comes from the Latin word panis, meaning bread, or panus, meaning "ear of millet." Philadelphicum means "of or from Philadelphia." Gattingeri is named after Augustin Gattinger (1825-1903), the person who discovered this subspecies.

Author: The Morton Arboretum