Andropogon gerardi, known commonly as big bluestem, turkeyfoot,tall bluestem, and bluejoint, is a tall grass native to much of the Great Plains and grassland regions of central and eastern North America.
Big bluestem is a perennial warm-season bunchgrass. It is tolerant of a wide range of soil conditions. The main roots are 6-10 ft (1.8-3.0 m) deep, and the plants send out strong, tough rhizomes, so it forms very strong sod. Depending on soil and moisture conditions, it grows to a height of 1-3 metres (3.3-9.8 ft). The stem base turns blue or purple as it matures.
Big bluestem blooms in the summer and seeds into the fall. The inflorescence (flower cluster) is a raceme of two to six, most commonly three, narrow spike-like racemes alternately arranged along the top of the stem. It somewhat resembles a turkey's foot. Each raceme contains pairs of spikelets. Each pair has a stalked spikelet with another stalkless spikelet at the base of the stalk. The stalkless spikelet usually has a fertile, perfect floret (with both female and male parts) and an awn (bristle), and the stalked spikelet is awnless, and is sterile or has a staminate (male) flower.
Big bluestem is a mid-successional grass in prairie and other grassland ecosystems. It grows in tall, dense stands that can out-compete other plant species. The stands grow until disturbance interrupts their spread. It is shade intolerant and is adapted to fire.
The grass and its variants are good forage for horses and cattle and can also be cut and used for hay. The grass is high in protein. While not considered the highest quality native forage found in the United States, it has long been considered a desirable and ecologically important grass by cattle ranchers and rangeland ecologists.
Big bluestem is cultivated by specialty plant nurseries for its drought tolerance and native status. It is often grown for wildlife gardens, natural landscaping, and grassland habitat restoration projects.
USDA GRIN rejects the spelling gerardii and provides reasoning for gerardi as being the correct spelling for the specific epithet of this taxon.Andropogon gerardii still makes appearances in various literature, including USDA publications.