Panicum sphaerocarpon Elliott

Panic Grass

Panicum sphaerocarpon plant

Family - Poaceae

Stems - To 60cm tall, erect, herbaceous, typically simple but sometimes branching in the fall, single or multiple from the base, glabrous. Nodes glabrous or with short appressed hairs.

Leaves - Leaves of basal rosette different than those of the stem. Basal leaves elliptic. Cauline leaves linear-lanceolate, to +/-20cm long, +/-2.5cm broad, sheathing, rounded a the base, glabrous on the surfaces, with hairs on the margins near the base. Some of the hairs with pustulate bases. Sheath glabrous but hairy on the margins.

Panicum sphaerocarpon leaf base

Inflorescence - A dense branching panicle to +10cm tall (long). Spikelets mostly at the tips of the panicle branches. The branches os the panicle mostly glabrous.

Panicum sphaerocarpon inflorescence

Flowers - Spikelets small, +/-1.5mm long, broadly elliptic to orbicular. Lower glume glabrous. Upper glume fine hairy (rarely glabrous), rounded at the apex, to 1.8mm long.

Flowering - May - September or July - November.

Habitat - Upland prairies, glades, ledges of bluffs, mesic to dry upland woods, bottoms, streambanks, disturbed sites, roadsides. Usually on acid substrates.

Origin - Native to U.S.

Other info. - This species can be found mostly in the lower 2/3 of Missouri. The plant is fairly easy to ID in the field because of its dense inflorescence, tiny spikelets, and dimorphic leaves.
There are two varieties of this species in Missouri. Variety isophyllum (shown above) has glabrous nodes and an inflorescence about twice as long as wide. Variety sphaerocarpon has pubescent nodes and an inflorescence that is about as long as wide.

Photographs taken on Stegal Mountain, MO., 7-15-03.