Diversity and classification of Andropogoneae

Page snapshot: Introduction to the classification, diversity, and distribution of grasses in Tribe Andropogneae.

Credits: Funded by the National Science Foundation. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Page by Elizabeth J. Hermsen.

Updates: Page last updated January 11, 2023.

Image above: Chinese silvergrass (Miscanthus sinensis), cultivated, Austria. Photo by Manfred Werner-Tsui (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, image cropped and resized).

Introduction

According to a recent classification by Welker et al. (2020), Tribe Andropoogneae is divided into 14 subtribes and includes more than 90 genera and more than 1200 species. The subtribes and examples of grasses within them are listed below. About 23 genera in Andropogoneae remain unclassified at the subtribe level because their relationships are not fully understood. As we learn more about the evolution of tribe Andropogoneae, these grasses will eventually be classified.

Diagram showing the relationships among the subtribes of grasses in Tribe Andropogoneae, with common names of examples of grasses in each subtribe listed below the subtribe names.

Relationships among the 14 subtribes in tribe Andropogoneae; genera not placed to a subtribe are not shown on this tree. This tree is adapted from Welker et al. (2020).

Subtribe Arthraxoninae

Subtribe Arthraxoninae includes only carpetgrass (Arthraxon), which has about seven species. This genus is widespread, occurring naturally in Africa, Australia, and Eurasia. It is introduced in Central and North America.

Photograph of small carpetgrass. Teh photo shows the ground covered with low-growing plants that have ovate leaves with wavy margins.

Small carpetgrass (Arthraxon hispidus), Bethel, Pennsylvania, U.S.A. Photo by Richard Gardner (iNaturalist, Creative Commons Attribution-NonCommercial 4.0 International license, image resized).

Subtribe Tripsacinae

Subtribe Tripsacinae has only two genera and more than 20 species. It includes gamagrass (Tripsacum), maize (Zea mays), and teosinte (several species of Zea), the wild relatives of maize. Subtribe Tripsacinae is the only subtribe of Andropogoneae native only to the Americas.

Maize is a widely grown cereal crop and is also used to produce biofuels (ethanol), sugar (high fructose corn syrup), corn starch, and other products. Eastern gamagrass (Tripsacum dactyloides) is cultivated as an ornamental.

2-panel figure showing the growth form of teosinte. Panel 1: Photograph of a teosinte plant showing its branching structure. Panel 2: Black and white drawing of a teosinte plant showing how it branches to form a clump. Details of the ears (female inflorescences) and a kernel are shown to the sides of the plant.

Teosinte plants. Left: Zea diploperennis. Right: Zea mays subspecies mexicana. Photo credits: Zea diploperennis by Jeffdelonge (Wikimedia Commons, Creative Commons Attribution-ShareAlike Unported license, image cropped and resized); Zea mays subspecies mexicana (Wikimedia Commons, via USDA PLANTS, public domain).

Photograph of maize. The photo shows a close-up rows of dried cornstalks with mature corn. The husk has been partially opened on one ear of corn, exposing the kernels. A combine is present in the left background, out of focus.

Corn (Zea mays) harvest. Photo by United Soybean Board (flickr, Creative Commons Attribution 2.0 Generic license, image resized).

Photograph of eastern gamagrass. The photo shows an inflorescence of eastern gamagrass oriented horizontally with reddish anthers dangling down.

Inflorescence of eastern gamagrass (Tripsacum dactyloides); the red structures hanging down are anthers. Photo by Agnieska Kwiecień, Nova (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license).

Subtribe Chionachninae

Subtribe Chionanchninae includes three genera and about 12 species. Grasses in this subtribe occur in South Asia to Australia and are relatively rare.

Photograph of an inflorescence of Job's tears. The photo shows a delicate inflorescence hanging vertically, The spikelets at the tip of the inflorescence (bottom of the image) are open, and light yellow anthers are protruding from them. The spikelets near the base of the inflorescence are closed.

Inflorescence of giant Job's tears (Polytoca gigantea) with open male spikelets. Photo by Dinesh Valke (flickr, Creative Commons Attribution-ShareAlike 2.0 Generic license, image cropped and resized).

Subtribe Rhytachninae

Subtribe Rhytachninae includes five genera and about 26 species of tropical grasses. An example of a grass from Rhytachninae is hippo grass (Vossia cuspidata), which is native large parts of Africa and southeast Asia and grows in freshwater.

Photograph of hippo grass. The photo shows a calm body of water with long grass growing at the edge. Papyrus looms over the grass in the background.

Hippo grass (Vossia cuspidata, foreground) and papyrus (Cyperus papyrus, a sedge, background) in Ngamiland North, Botswana. Photo by Robert Taylor (iNaturalist, Creative Commons Attribution 4.0 International license, image resized).

Subtribe Chrysopogoninae

Subtribe Chrysopogoninae includes one genus (false beardgrass, Chrysopogon) and about 50 species of warm temperate to tropical grasses. Most species are found in Africa, Asia, and Australia.

Photograph of Chrysopogon filipes growing in the Macleay River, Australia. The photo shows a dry riverbed with large cobbles and clumps of grass growing in it. The grass is a mix of green and yellow dried stalks. The grass clumps are leaning toward the right side of the image.

Chrysopogon filipes, Macleay River, New South Wales, Australia. Photo by Harry Rose (flickr, Creative Commons Attribution 2.0 Generic license, image resized).

Subtribe Rottboelliinae

Subtribe Rottboellinae includes three genera and about 13 species. These grasses are native to Africa, Asia, and Australia.

Job's tears (Coix lachryma-jobi) has been widely introduced outside of its native range and is used in herbal medicine and as a grain in some parts of the world. Itchgrass or raoulgrass (Rottboellia cochinchinensis), which is now also widely distributed outside of its native range, is a roadside and agricultural weed, infesting fields of corn, cotton, peanuts, soybean, and sugarcane.

Photograph of cultivated Job's tears. The photo shows a close-up of a group of spikelets. The are large and ovate and vary in color from light gray to dark gray to beige.

Job's tears (Coix lachryma-jobi), cultivated, Poland. Photo by Salicyna (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized).

Photograph of itchgrass. Teh photo shows a tangle of grass cascading down from a rusty chainlink fence.

Itchgrass (Rottboellia cochinchinensis) in Houston, Texas, 2018. Photo by dan_johnson (iNaturalist, Creative Commons Attribution-NonCommercial 4.0 International license, image resized)

Subtribe Ratzeburgiinae

Subtribe Ratzenburgiinae includes 11 genera and nearly 90 species. Grasses in this subtribe are native to Africa, Asia, and Australia, and include centipede grass (Eremochloa), pitscale grass (Hackelochloa), jointgrass (Hemarthria), and jointtail grass (Mnesithea).

Limpo grass (Hemarthria altissima), native to Eurasia, is used as a tropical forage grass.

2-panel image showing photos of fringed centipede grass. Panel 1: Image of grass culms bearing apical inflorescences. Panel 2: Close-up of an inflorescence. The inflorescence has white hairs and pinkish-purple stigmas and stamens protruding.

Fringed centipede grass (Eremochloa ciliaris), Sze Pai Shek Shan, China. Photo by agnestrekker (iNaturalist, CC0 1.0 Universal/public domain dedication).

Photograph of limp grass. The photo shows a large clump of long, green grass. Some of the grass stems have inflorescences.

Limpo grass (Hemarthria altissima), Maui, Hawaii. Photo by Forest & Kim Starr (Wikimedia Commons, Creative Commons Attribution 3.0 United States license, image resized).

Subtribe Ischaeminae

Subtribe Ischaeminae has about four genera and 150 species native to the tropics worldwide. Examples of members of this subtribe include sabaigrass (Eulaliopsis) and murainagrass (Ischaemum).

Photograph of Ischaemum triticeum, a type of murainagrass, growing on a sandy beach. The photo shows a tangle of green grass, dry yellow grass leaves, and flowering stalks.

Ischaemum triticeum, Australia. Photo by Harry Rose (flickr, Creative Commons Attribution 2.0 Generic license, image resized).

Subtribe Germainiinae

Subtribe Germainiinae has five genera and 44 species. Four of the genera are native to Asia and Australia, whereas satintail (Imperata) is more widespread, found in the Americas, Africa, and Eurasia.

This subtribe includes cogongrass (Imperata cylindrica), a grass native to parts of Africa and Asia that is now a globally invasive weed. Nevertheless, one cultivar of cogongrass, Japanese blood grass (Imperata cylindrica 'Red Baron') is grown as an ornamental. Another ornamental grass, baby bamboo or baby panda grass (Pogonatherum paniceum), is also in this subtribe.

Photograph of cogongrass. The photo shows a large field of tall, green grasses with feathery while inflorescences.

Cogongrass (Imperata cylindrica) in Gauteng, South Africa. Photo by JMK (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image resized).

Photograph of cultivated baby bamboo. The photo shows a clump of low-growing grass with short, spiky-looking leaves.

Baby bamboo (Pogonatherum paniceum, not a true bamboo), cultivated. Photo by David J. Stang (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized).

Subtribe Sorghinae

Subtribe Sorghinae has four genera and fewer than 40 species. The largest and most important genus is sorghum (Sorghum), which includes one of the world's major cereal crops (Sorghum bicolor). Johnsongrass (Sorghum halepense) is a weed that is found throughout much of the world.

Photograph showing a field densely planted with sorghum. Each sorghum plant has large cluster of red caryopses near its apex. A low hill with patches of forest and open field rises in the background.

Cultivated sorghum (Sorghum bicolor), France. Photo by Jean Weber (flickr, Creative Commons Attribution 2.0 Generic license, image resized).

Photograph showing Johnsongrass growing in Missouri. The photo shows a group of tall grass plants with inflorescences at the edge of an open field, with trees in the background on the other side of the field.

Johnsongrass (Sorghum halepense) growing in Missouri, U.S.A. Photo by florawhite (iNaturalist, Creative Commons Attribution 4.0 International license, image resized).

Subtribe Saccharinae

Subtribe Saccharinae has three genera and more than 60 species. These include silvergrass (Miscanthus), which is native to Africa, Asia, and Australia, and plumegrass (Saccharum), found throughout the tropics. The third genus, Pseudosorghum, is native to Asia.

Giant miscanthus (Miscanthus x giganteus) is a hybrid species that is grown for use as a biofuel. Some other species of silvergrass like Amur silvergrass (Miscanthus saccariflorus) and Chinese silvergrass (Miscanthus sinensis), are grown as ornamentals. At least one of these, Chinese silvergrass, is also weedy in some regions. Sugar cane (Saccharum officianarum), originally native to New Guinea, is now widely cultivated in the tropics as a source of sugar.

Photograph of a cultivated field of giant miscanthus. A man in a dark jacket and jeans stands in front of the giant miscanthus, holding what appears to be a measuring stick. The stems of the grasses are about twice as tall as the man. The grasses are brown and yellow at the base, green near the top, with leaves all the way up their stems. The inflorescences on top of the stems are silvery white and feathery.

Giant miscanthus (Miscanthus x giganteus), cultivated in Germany. Photo by Hamsterdancer (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, image resized).

Photograph of a field of Chinese silvergrass in Hyogo Prefecture, Japan. The photo shows low rolling hills with a dense grassy cover. The grasses are tall with striking, white, plumelike inflorescences.

Chinese silvergrass (Miscanthus sinensis), Tonomine Highlands, Hyogo Prefecture, Honshu Island, Japan. Photo by 663highland (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, image resized).

Photograph of a field of cultivated sugarcane in Australia. The sugarcane is in a dense planting with a dirt road running along its edge. The grasses are yellowish at the base, green near their tops.

Field of sugar cane (Saccharum officianarum), Queensland, Australia. Photo by Richard Riley (flickr, Creative Commons Attribution 2.0 Generic license, image cropped and resized).

Subtribe Apludinae

Subtribe Apludineae has about seven genera and nearly 70 species and is found from tropical to temperate regions worldwide. Examples of members of this subtribe include Mauritian grass (Apluda), Java grass (Polytrias), Indiangrass (Sorghastrum), and crinkleawn grass (Trachypogon).

Photograph of an inflorescence of Mauritian grass. The photo shows a delicate inflorescence oriented horizontally with its tip to the left. The spikelets are widely spaced on a thin, red stalk. Many of the spikelets are open, exposing minute anthers and fuzzy white stigmas.

Mauritian grass (Apluda mutica), Andhra Pradesh, India. Photo by J.M.Garg (Wikimedia Commons, Creative Commons Attribution 3.0 Unported license, image resized).

Photograph of an inflorescence of Java grass. The photo shows the top of an inflorescence, with its apex to the right. The spikelets are dry and brown and organized on a yellow, zig-zagging stalk. The spikelets have awns, each with a red, twisted base and long, yellow extension oriented horizontally. The whole structure has hairs.

Inflorescence of Java grass (Polytrias indica), showing twisted awns. Photo by Tracey Slotta (USDA PLANTS via Wikimedia Commons, public domain).

Photograph of Indiangrass. The photo shows long grass with feathery yellow inflorescences growing in an open field.

Indiangrass (Sorgahstrum nutans), San Antonio, Texas, U.S.A. Photo by prairie_rambler (iNaturalist, Creative Commons Attribution 4.0 International license, image cropped and resized).

Subtribe Anthistiriinae

Subtribe Anthistiriinae has nine genera and more than 200 species. These grasses are distributed around the world. Examples of grasses in this subtribe include beardgrass (Bothriochloa), bluestem (Dichanthium), mock bluestem (Euclasta), tanglehead (Heteropogon), and kangaroo grass (Themeda). Tanglehead and kangaroo grass are dominant grasses in some C₄ grasslands, particularly in Africa, Asia, and South America.

This subtribe includes grasses like tanglehead (Heteropogon contortus), Caucasian bluestem (Bothriochloa bladhii), and yellow bluestem (Bothriochloa ischaemum) that are considered weeds in some regions where they have been introduced. Lemon grass (Cymbopogon citratus and C. flexuosus) is used to add flavor to food, and citronella grass (Cymbopogon nardus) is cultivated to produce citronella oil.

Photograph of kangaroo grass, also called red grass, in Kruger National Park, South Africa.

Kangaroo grass or red grass (Themeda triandra), Kruger National Park, South Africa. Photo by Bernard DuPont (flickr, Creative Commons Attribution-ShareAlike 2.0 Generic license, image resized).

Photograph of tangelhead growing near a roadside in Australia. The photo shows tall grass plants gracefully arcing to the right, each with a dark-colored inflorescence. A bit of road can be seen at the right side of the image in the middle ground.

Tanglehead (Heteropogon contortus), Australia. Photo by Harry Rose (flickr, Creative Commons Attribution 2.0 Generic license, image cropped and resized).

Photograph showing three spikelets of yellow bluestem. Each spikelet is purplish in color with sparse hairs and a single, twisted awn extending from its apex.

Spikelets of yellow bluestem (Bothriochloa ischaemum) showing long awns. Photo by Stefan.Iefnaer (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image resized).

Photograph showing a bowl of food (apparently curry, it is a yellow liquid with chunks of plants floating in it) with a bundle of lemongrass on a slice of wood next to it.

Lemongrass (Cymbopogon citratus) is used in cooking. Photo by Herusutimbul (Wikimedia, Creative Commons Attribution 4.0 International license, image resized).

Subtribe Andropogoninae

Subtribe Andropogoninae has eleven genera and about 290 species widely distributed around the world. Examples include bluestem (Andropogon), thatching grass (Hyparrhenia), and little bluestem (Schizachyrium).

Photograph of big bluestem growing near a roadside in Minnesota, U.S.A. The photo shows tall, reddish grass plants with inflorescences on long stalks growing in a line extending from the right foreground to the middle-left horizon, with mowed lawn to the left. Two roadsigns and trees can be seen near the horizon, with a building on on the right.

Big bluestem (Andropogon gerardii) growing on a roadside in Minnesota, U.S.A. Photo by Matt Lavin (flickr, Creative Commons Attribution-ShareAlike 2.0 Generic license, image resized).

Photograph showing thatching grass growing in Spain. The photo shows clumps of grass growing in two rows extending from left to right. The ground appears to be rock or packed earth.

Thatching grass (Hyparrhenia hirta), Cáceres, Spain. Photo by Luis Fernández García (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized).

Photograph showing a close-up of little bluestem inflorescences. The photo shows a cluster of red grass stalks with green leaves and feathery off-white inflorescences.

Little bluestem (Schizachyrium scoparium), Green County, Wisconsin, U.S.A. Photo by Joshua Mayer (flickr, Creative Commons Attribution-ShareAlike 2.0 Generic license, image resized).

Grasses not in a subtribe

Currently, 23 genera and about 125 species of grasses in tribe Andropogoneae have not yet been placed in a subtribe. Examples of these include balsamscale grass (Elionurus), moco de pavo (Eriochrysis), and browntop (Microstegium).

Japanese stiltgrass (Microstegium vimineum) is a grass native to Asia that is an invasive weed in forests of the eastern United States. Ravenna grass (Tripidium ravennae), native to Africa and Eurasia, is used as an ornamental in the U.S. but is also considered weedy. Frost grass (Spodiopogon sibiricus), native to eastern Asia, is used as an ornamental.

Photograph of Japanese stiltgrass growing in a forest in Maryland, U.S.A. The photo shows a grass with strap-shaped leaves completely carpeting the forest floor, with the brown trunks of trees rising above.

Carpet of Japanese stiltgrass (Microstegium vimineum) in Greenbelt Park, Maryland, U.S.A. This grass is considered an invasive weed in parts of the eastern U.S. Photo by mellis (iNaturalist, Creative Commons Attribution 4.0 International license, image resized).

2-panel image showing photos of ravenna grass growing in Texas, U.S.A. Panel 1: Photo of a clump of ravenna grass growing on a steep dirt bank, with conifers rising in the background at the top of the bank. Panel 2: Detail of an inflorescence of ravenna grass. The flowering stalk is yellowish-brown and appears rather spent. Conifers can be seen in the background.

Ravenna grass (Tripidium ravennae), Sweetwater, Texas, U.S.A. This grass is considered an invasive weed in parts of the United States. Photos by ck2az (iNaturalist, Creative Commons 4.0 International license, images cropped and resized).

Photograph of frost grass growing in the Russian Far East. The photo shows feathery, delicate, off-white inflorescence suspended on thin stems.

Frost grass (Spodiopogon sibricum), Russian Far East. Photo by Valery Kambalin (iNaturalist, Creative Commons Attribution-NonCommercial 4.0 International license, image resized).

Resources

Websites

Angiosperm Phylogeny Website (P. F. Stevens): http://www.mobot.org/MOBOT/research/APweb/

GrassWorld: https://grassworld.myspecies.info/en

Imperata cylindrica (Bugwood Wiki): https://wiki.bugwood.org/Imperata_cylindrica#cite_note-holm-2

Invasive Plant Atlas of the United States: https://www.invasiveplantatlas.org/grass.cfm

Itchgrass (Texas Invasive Species Institute): http://www.tsusinvasives.org/home/database/rottboellia-cochinchinensis

Kew Plants of the World Online: https://powo.science.kew.org/

Plant Finder (Missouri Botanical Garden): https://www.missouribotanicalgarden.org/plantfinder/plantfindersearch.aspx

Books, articles, and reports

Boyd, J. D., Jr., V. Maddox, and R. Westbrooks. 2018. Itchgrass. Mississipi State University Extension Publication 3186 (POD-02-18), 2 pp. http://extension.msstate.edu/publications/itchgrass

Scientific literature

Arthan, W., L. T. Dunning, G. Besnard, S. Manzi, E. A. Kellogg, J. Hackel, C. E. R. Lehmann, J. Mitchley, and M. S. Vorontsova. 2021. Complex evolutionary history of two ecologically significant grass genera, Themeda and Heteropogon (Poaceae: Panicoideae: Andropogoneae). Botanical Journal of the Linnean Society 196: 437-455. https://doi.org/10.1093/botlinnean/boab008

Soreng, R. J., P. M. Peterson, K. Romaschenko, G. Davidse, J. K. Teisher, L. G. Clark, P. Barberá, L. J. Gillespie, and F. O. Zuloaga. 2017. A worldwide phylogenetic classification of the Poaceae (Gramineae) II: An update and a comparison to two 2015 classifications. Journal of Systematics and Evolution 55: 259-290. https://doi.org/10.1111/jse.12262

Welker, C. A. D., M. R. McKain, M. C. Estep, R. S. Pasquet, G. Chipabika, B. Pallangyo, and E. A. Kellog. 2020. Phylogenomics enables biogeographic analysis and subtribal classification of Andropogoneae (Poaceae--Panicoideae. Journal of Systematics and Evolution 58: 1003-1030. https://doi.org/10.1111/jse.12691

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