Andropogon glomeratus
(bushy bluestem)

Preferred Common Name

• bushy bluestem

Other Scientific Names

• Anatherum macrourum (Michx.) Griseb.
• Andropogon corymbosus (Hack.) Nash
• Andropogon corymbosus var. abbreviatus (Hack.) Nash
• Andropogon densus Desv. ex Ham.
• Andropogon glaucopsis (Elliott) Steud.
• Andropogon glomeratus var. abbreviatus (Hack.) Scribn.
• Andropogon glomeratus var. corymbosus (Hack.) Scribn.
• Andropogon glomeratus var. glaucopsis (Elliott) C.Mohr
• Andropogon glomeratus var. glomeratus
• Andropogon glomeratus var. hirsutior (Hack.) C.Mohr
• Andropogon glomeratus var. pumilus (Vasey) Dewey
• Andropogon glomeratus var. tenuispatheus Nash
• Andropogon hirsutior (Hack.) Weakley & LeBlond
• Andropogon macrourum var. abbreviatus Hack.
• Andropogon macrourum var. corymbosus Chapm. ex Hack.
• Andropogon macrourus Michx.
• Andropogon macrourus var. abbreviatus Hack.
• Andropogon macrourus var. corymbosus Hack.
• Andropogon macrourus var. glaucopsis Elliott
• Andropogon macrourus var. hirsutior Hack.
• Andropogon macrourus var. pumilus Vasey
• Andropogon montanus var. glaucopsis (Steud.) Hack.
• Andropogon spathaceus Trin.
• Andropogon tenuispatheus (Nash) Nash
• Andropogon virginicus f. hirsutior (Hack.) Fernald & Griscom
• Andropogon virginicus f. tenuispatheus (Nash) Fernald
• Andropogon virginicus var. abbreviatus (Hack.) Fernald & Griscom
• Andropogon virginicus var. corymbosus (Hack.) Fernald & Griscom
• Andropogon virginicus var. glaucopsis (Elliott) Hitchc.
• Andropogon virginicus var. hirsutior (Hack.) Hitchc.
• Andropogon virginicus var. tenuispatheus (Nash) Fernald & Griscom
• Capillipedium parviflorum f. glaucopsis (Steud.) Roberty
• Cinna glomerata Walter
• Dimeiostemon macrourus (Michx.) Raf. ex B.D.Jacks.
• Sorghum glomeratum (Walter) Kuntze

International Common Names

• English: broomsedge bluestem; bushy beardgrass; bushy bluestem; bushy broom grass; chalky bluestem
• Spanish: cola de zorra; mato escoba del fogón; matojillo; pasto; popotillo matorralero; rabo de mula; tallo azul matorralero; yerba barbuda

Local Common Names

• Mexico: ch’it-suuk
• USA: wi’tsura’k

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Monocotyledonae
•                     Order: Cyperales
•                         Family: Poaceae
•                             Genus: Andropogon
•                                 Species: Andropogon glomeratus

Andropogon is a genus of plants in the grass family. This genus comprises 125 APG-III accepted and 64 unresolved species (The Plant List, 2013). Andropogon taxa are widely distributed, predominantly in the tropics and sub-tropics (Watson and Dallwitz, 1992). This genus owes its name to the Greek words aner (from andr-, man) and pogon (beard), alluding to villous pedicels of sterile and male-only spikelets (Watson and Dallwitz, 1992).

Andropogon glomeratus was described in 1888 by Britton et al. (1888). In the past, several authorities considered A. glomeratus and A. virginicus as one species; however, the two grasses are distinct and consistent in appearance and are currently recognized as separate species (Newman and Gates, 2006). The Latin epithet glomeratus refers to this species’ compound inflorescence (Johson and Smith, 1972). 

Hybridization can occur with A. longiberbis (Campbell, 1982) and with A. virginicus (Campbell, 2003).

Adapted from Clayton et al. (2015):

A. glomeratus is perennial plant, with erect, strong stalks that grow up to 1.5 m tall. These stalks are often ramified at the base, usually scabrous, sometimes smooth. Ligules are short (0.6-2.2 mm), brown, sometimes ciliate. Foliar blades 30-400 mm long, 2.9-9.5 mm wide, glabrous or sparsely to densely pubescent, hairs usually spreading, rarely appressed. Synflorescence compound; paniculate and dense. Inflorescence terminal and axillary, 300 mm long, dense, oblong, composed of racemes (20-30 mm long) disposed in pairs, sometimes in groups of 3; subtended by a spatheole; embraced at the base by subtending leaf. Spatheole lanceolate; 15-30 mm long. Peduncle 5-10 mm long; hirsute above.

Spikelets ascending, or spreading; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; curved; plumose. Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; membranous; 2-keeled; keeled laterally. Lower glume intercarinal veins absent. Lower glume surface concave. Upper glume lanceolate; membranous; 1-keeled; 1-veined. Upper glume lateral veins absent. Upper glume muticous. Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; hyaline. Fertile lemma lanceolate; hyaline; without keel. Lemma apex lobed; 2-fid; awned; 1-awned. Principal lemma awn from a sinus; straight; 10-20 mm long overall. Palea absent or minute. 3 Anthers. Caryopses ca. 3 mm long.

The introduction history of this species is unknown (HISC, 2015).

Soil drainage

• impeded
• seasonally waterlogged

Soil reaction

• acid

Soil texture

• medium

Special soil tolerances

• infertile

Natural Dispersal

A. glomeratus seed is dispersed by wind (Cain et al., 1998). PIER (2008) stated that this species’ occurrence around waterways suggests seeds can also be dispersed by water.

Accidental Introduction

This species can potentially be introduced as a seed contaminant (Quattrocchi, 2006) or through imported sand or gravel, or machinery (PIER, 2008). Seeds can also be dispersed in dry arrangements as the dry seed stalks remain mostly intact through winter and make attractive cut material (PIER, 2008).

Intentional Introduction

Because of its popularity as an ornamental (Wolfe and Zajicek, 1998), there is a risk of further intentional introduction.

Due to its potential as a seed contaminant, Wiersema and León (1999) considered A. glomeratus an economically important weed. Although rarely occurring in crops it may affect e.g. rice as an alternative host of Periconia echinocloae, and sugar cane as an alternative host of Sporisorium culmiperdum and of sugarcane mosaic virus.

In some areas of Hawaii, A. glomeratus has been noted to outcompete native plant species such as Heteropogon contortus, Dodonaea viscosa and the endemic Vaccinium reticulatum (Taylor, 1982).

Smith et al. (1980) have described the increase of Andropogon populations after fire (Smith et al., 1980). A. glomeratus is highly flammable throughout most of the year (Taylor, 1982), and so stands of this species could change fire regimes, whereby fires promote the conditions necessary to increase fire frequency and size by increasing the continuity and/or fuel loadings of alien grasses (Smith and Tunison, 1992).

• Invasive in its native range
• Proved invasive outside its native range
• Has a broad native range
• Highly adaptable to different environments
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Has high reproductive potential
• Has propagules that can remain viable for more than one year
• Reproduces asexually

• Ecosystem change/ habitat alteration
• Increases vulnerability to invasions
• Modification of fire regime
• Transportation disruption

• Competition - monopolizing resources
• Competition - strangling
• Competition (unspecified)
• Pest and disease transmission
• Hybridization

• Highly likely to be transported internationally accidentally
• Highly likely to be transported internationally deliberately
• Difficult to identify/detect as a commodity contaminant
• Difficult/costly to control

Social Benefit

A. glomeratus is used as an ornamental grass in landscapes because of its showy plumes that turn a rust colour during late autumn and early winter. In Mexico, this species is used for medicinal purposes and for the elaboration of traditional handicrafts, as well as for fodder (Mejía-Saulés and Dávila Aranda, 1992). As a forage grass, however A. glomeratus rates low in desirability (Newman and Gates, 2006). According to Newman and Gates (2006), this species is more palatable during the early spring, when comestibility is increased after a late winter burning.

Boughman and Oxendine (2004) listed several uses for this species in North America. In Cherokee traditional medicine combined with amaranth, it was used in the eleaboration of green corn medicine (a medicine used in a ceremony of the same name). Lumbee people use the soaked roots of A. glomeratus in an infusion to treat jaundice, frostbine and diarrhea. The Lumbee also use this species as an analgesic, febrifuge and antidiahrreal (Boughman and Oxendine, 2004).

Environmental Services

According to Newman and Gates (2006), some wildlife benefits from A. glomeratus: the junco finch (Junco spp.) and tree sparrow (Spizelloides arborea) eat the seeds; and white-tailed deer (Odocoileus virginianus) and rabbits browse this species. A. glomeratus also provides good cover for small animals such as mottled ducks (Anas fulvigula) and fawns (white-tailed deer) (Newman and Gates, 2006).