''Andropogon gerardi'', commonly known as big bluestem, is a species of tall

grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and spe ...

native to much of the

Great Plains The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include th ...

and

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

regions of central and eastern North America. It is also known as tall bluestem, bluejoint, and turkeyfoot.

Taxonomy

''Andropogon gerardi'' was formally named in 1792 by Fulgenzio Vitman. It was named for French botanist Louis Gérard, who had first described the plant from specimens that had been cultivated in

Provence Provence is a geographical region and historical province of southeastern France, which stretches from the left bank of the lower Rhône to the west to the France–Italy border, Italian border to the east; it is bordered by the Mediterrane ...

, France.

Kew Kew () is a district in the London Borough of Richmond upon Thames. Its population at the 2011 census was 11,436. Kew is the location of the Royal Botanic Gardens ("Kew Gardens"), now a World Heritage Site, which includes Kew Palace. Kew is ...

International Plant Names Index The International Plant Names Index (IPNI) describes itself as "a database of the names and associated basic bibliographical details of seed plants, ferns and lycophytes." Coverage of plant names is best at the rank of species and genus. It inclu ...

and

USDA The United States Department of Agriculture (USDA) is an United States federal executive departments, executive department of the Federal government of the United States, United States federal government that aims to meet the needs of commerc ...

Germplasm Resources Information Network Germplasm Resources Information Network or GRIN is an online USDA National Genetic Resources Program software project to comprehensively manage the computer database for the holdings of all plant germplasm collected by the National Plant Germpla ...

reject the spelling ''gerardii'' and provide reasoning for ''gerardi'' as being the correct spelling for the specific epithet of this taxon. ''Andropogon gerardii'' still makes appearances in various literature, including other USDA publications.

Description

Big bluestem is a

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

warm-season

bunchgrass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perennia ...

. It is tolerant of a wide range of

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

conditions. The main

root In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...

s are deep, and the plants send out strong, tough

rhizome In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...

s, so it forms very strong sod. Depending on soil and moisture conditions, it grows to a height of . The stem base turns blue or purple as it matures. Big bluestem blooms in the summer and seeds into the fall. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

(cluster of flowers) is a

raceme A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...

of two to six, most commonly three, narrow spike-like racemes alternately arranged along the top of the stem. It somewhat resembles a

wild turkey The wild turkey (''Meleagris gallopavo'') is an upland game bird native to North America, one of two extant species of Turkey (bird), turkey and the heaviest member of the order Galliformes. It is the ancestor to the domestic turkey (''M. g. dom ...

's foot. Each raceme contains pairs of

spikelet A spikelet, in botany, describes the typical arrangement of the inflorescences of grasses, sedges and some other monocots. Each spikelet has one or more florets. The spikelets are further grouped into panicles or spikes. The part of the sp ...

s. 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 This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary ...

(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.

Ecology

Big bluestem is a mid- successional grass in

prairie Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...

and other grassland ecosystems. It grows in tall, dense stands that can outcompete other plant species. The stands grow until disturbance interrupts their spread. It is shade intolerant and is adapted to fire. It is a host to larvae of several species of butterflies, including the arogos skipper, byssus skipper, cobweb skipper, common wood nymph, Delaware skipper, and dusted skipper. The larvae of the leaf beetle '' Diabrotica cristata'' feed on the roots and the adults visit the flowers of other species of prairie flowers. Many ants decorate their nests with the seeds, including '' Formica glacialis'', '' F. montana'', and '' F. subsericea''. Several species of ants, such as ''F. glacialis'', ''F. montana'', ''F. subsericea'', '' Lasius minutus'', and '' L. umbratus'' build nests around the base of this bunchgrass, forming large soil mounds. In larger mounds, the nest is shared by multiple species of ants, and is "likened to an apartment complex with each ant species in its own nest partition". Up to 12 species of ants have been recorded in mounds found in the Chicago region. The rust fungus '' Puccinia andropogonis'' forms black telia on the leaves.

Uses

The grass and its variants are good

forage Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used m ...

for

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...

s and

cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

, 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 garden A wildlife garden (or habitat garden or backyard restoration) is an Biophysical environment, environment created with the purpose to serve as a sustainable haven for surrounding wildlife. Wildlife gardens contain a variety of habitats that cater t ...

natural landscaping Natural landscaping, also called native gardening, is the use of native plants including trees, shrubs, groundcover, and grasses which are local to the geographic area of the garden. Benefits Maintenance Natural landscaping is adapted to t ...

, and

habitat restoration projects. Due to its high

biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

, big bluestem is being considered as a potential feedstock for

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

production.

Symbols

''Andropogon gerardi'' is the state grass of

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

and

Missouri Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...

and the official prairie grass of

Manitoba Manitoba is a Provinces and territories of Canada, province of Canada at the Centre of Canada, longitudinal centre of the country. It is Canada's Population of Canada by province and territory, fifth-most populous province, with a population ...

References