Type of Plant: Native warm-season grass, a prairie tallgrass
Identification Helps: Big bluestem is a common tallgrass of Ohio prairies. It grows up to 8' or more. At maturity in late summer, the grass has four or five "turkey-foot" fingers of the seedhead (see illustration). Separating this species from the other two common prairie tallgrasses, Indiangrass (Sorghastrum nutans), and switchgrass (Panicum virgatum) before seedheads appear in late summer is done by checking the nodes, where the leaves attach to the stem. Big bluestem has no noticeable features at the node. Switchgrass has a nest of hairs on the leaf base at the node, and Indiangrass has a pair of "ears" projecting up from the node when the leaves are pulled away from the stem. Seedling or young big bluestems have hairs along the stems near the ground.
Preferred Growing Conditions in the Wild:Big blustem grows naturally in prairies and soils of average (mesic, pronounced "MEES-ik " or "MEZ-ik") moisture availability. Extremely dry or wet sites are not favorable. The grass is very common on prairies, but it also grows in flood plains. Occasionally, large natural stands are found on railroad rights of way and other open areas. Like most prairie plants, the grass requires un-shaded conditions.
Preferred Soils: The species grows in almost all soil types, but does not do well in continually wet soils.
Seasons of Growth and Bloom:New seasonal growth erupts from existing root crown in mid- to late April. Leafy growth occurs into July, with stems forming in late July. Seed heads form in mid- to late August. Seeds are formed in September and begin to drop in October.
Natural Distribution in Ohio: Big bluestem is found naturally throughout the state. In presettlement times, it was found on virtually all Ohio prairies, from small woodland prairie openings, to giant prairie landscapes such as the Darby Plain, Sandusky Plains, and all of the other large Ohio prairies.
Description and General Information:Big bluestem is known as "The King of the Prairie," the quintessential prairie grass. It is found on virtually all high quality prairie remnants. In pristine prairie it composes anywhere from 40 to 60% or so of the plant biomass. It's seedhead is shown on the OPA logo.
More of a big bluestem grass plant is underground than above ground, with up to 60% of the plant as roots and rhizomes. In early growth, big bluestem starts out as a "clump grass," growing as individual plants that form individual clumps. But as a prairie matures, the big bluestem clumps can grow together and form a dense grass sod.
The oldest plant in Ohio is probably not any tree. It may well be a big bluestem plant on an Ohio prairie. Big bluestem is a perennial plant, meaning that it re-grows each year from dormant rhizomes underground. This annual re-growth from underground stems (the rhizomes) can occur for centuries, until something physically destroys the grass clump, such as a plow or bulldozer.