Fall Panicum
Panicum dichotomiflorum

Description: This native grass is a summer annual about 1½–4' tall. It is often tufted at the base, sending up multiple culms (stems) that are ascending to erect. The culms are some shade of light green, terete, hairless, and largely covered by the sheaths; sometimes they branch and develop secondary culms. The blades of the alternate leaves are up to 1½' long and ¾" across, although they are usually about one-half this size. The leaf blades are medium green, linear, flat, hairless or nearly so, and rough long the margins; they usually spread outward and are rather floppy. The leaf sheaths are light green, terete or somewhat flattened, hairless, and finely veined; sometimes they are pale yellowish green or pale reddish green. The ligules have straight white hairs about 2 mm. long.

Inflorescence & Leaves

The central culm and secondary culms (if any) terminate in airy panicles of spikelets about ½–1¼' long and half as much across. Sometimes the panicles are barely exerted from the uppermost sheath and rather conical in shape toward the bottom, otherwise they are fully exerted and pyramidal in shape. The branchlets of each panicle are very slender, light green, glabrous, and spreading to ascending; they are straight rather than squiggly-wiry. The small spikelets are about 3 mm. long (rarely 2 mm. long), light green or purplish green, hairless, and ovoid-oblongoid in shape; each spikelet has 2 glumes and 2 lemmas. The first glume is about one-fourth the length of the spikelet (less than 1 mm.), while the second glume is the same length as the spikelet. The outer lemma is also the same length of the spikelet. Together, the second glume and outer lemma enclose the inner lemma and floret of the spikelet, which has conspicuous longitudinal veins along its outer surface. Each floret has an ovary, 2 feathery stigmas, and 3 anthers. The blooming period occurs during late summer into the fall. Pollination is by wind. Each spikelet produces a single grain about 2 mm. long that is ovoid, hairless, and somewhat flattened. The root system is fibrous. This grass spreads by reseeding itself.

Cultivation: This grass is typically found in full or partial sun in moist to mesic locations. It tolerates different kinds of soil, but prefers a fertile loam, clay loam, or silty loam. The size of each plant can be quite variable depending on growing conditions. Most growth occurs during the hot weather of summer because of its C4 metabolism.

Close-up of Sheath & Leaf