[NOTE: Indiangrass is listed as the state grass in official literature about Oklahoma emblems and symbols. I have not been able to locate any legislation which documents the official adoption of Indiangrass as the official Oklahoma state grass, although one source lists 1972 as its date of adoption.]
Indiangrass, or Little Bluestem, is a native warm-season prairie bunchgrass widely distributed in the United States throughout the Great Plains from Canada south to the Gulf of Mexico.
Both cold and drought tolerant, Indiangrass is a vigorous and robust perennial. Its roots can lay dormant for up to 5 years, waiting for better growing conditions. Fertile bottom soils with protection from the wind are the prime conditions for Indiangrass, but it also grows in sandy soils and on dry slopes, and can be found in almost any other soil type.
Stems grow from 3 to 5 feet tall, although they may reach as high as 8 to 10 feet. Blue-green leaves are smooth and flat, a half inch wide, elongated, narrow at the base. The panicle, or flower stem, is 8 to 12 inches long and bronze to yellow in color, turning into a golden plume when the seeds are produced. The plant spreads both by self-seeding and by underground rhizomes, which are short and scaly with fuzzy nodes.
As a forage crop, Indiangrass is most useful in the Central and Southern Great Plains. Domestic and wild grazing animals find it quite palatable while succulent (green); it can also be cut for hay.
This website at Purdue University has several detailed pictures of Indiangrass.