Grasses in the area of Burke Park (mostly a dry site or sagebrush steppe habitat)

The following grass species not only dominate the human landscape in Montana, but many are common to the sagebrush steppe and a couple to riparian settings. Samples of these grasses will be provided during the lecture and indoor lab sessions. Be sure to “key out” all of these species on your own time using the keys provided in either the Grasses of Montana or the Vascular Plants of Montana.

Tribe Triticeae (wheat grasses, notice the characteristic inflorescence, which is a bilateral terminal spike)

13. Agropyron cristatum. An introduced perennial bunchgrass, each stem usually bearing inflorescence. Planted very widely throughout Montana and the west for range improvement and CRP. Note the very short internodes of the spike inflorescence, and the spikelets that diverge from rachis at 45 degree angle or greater (often referred to as pectinate, "comb-like" or "crested"). This species has a variable inflorescence morphology

but always with short internodes between spikelets.

14. Agropyron dasystachym (Elymus lanceolatus). Thick spike wheatgrass. Perennial native bearing stout rhizomes, stems and leaves often glaucous (bluish green), spike inflorescence with short internodes, lemmas hairy, glumes narrow at the base and with distinct veins, leaf blades usually stiff and inrolled, common throughout Montana and inhabiting dry shrubby grasslands, often planted or escaping along roadsides, thrives under heavy grazing. Similar to western wheatgrass (A. smithii) and distinguished essentially by its broader glumes.

15. Agropyron intermedium (Thinopyrum intermedium). Intermediate wheatgrass. This species is an introduced perennial, usually strongly rhizomatous and occurring in diffuse patches, inflorescence has one spikelet per node, spikelets without awns (compared to A. repens on the right), with stiff glumes each usually bearing an apical notch, leaves usually stiff and often flat, sheath with a distinctive ciliate margin at least on the lower leaves, an introduced forage grass traditionally used in range improvement, commonly escaping along roadsides and in vacant lots, in dry sites or on well-drained soils.

16. Agropyron spicatum (Pseudoroegneria spicatum). Bluebunch wheatgrass, and also known as the Montana State Grass. A perennial native bunchgrass, stems often loosely bunched, the spikelets appressed to the main rachis and separated by long internodes, awns if present come from the lemmas and curve outward at maturity, widespread in Montana and ranging from open grasslands to forest understory, the “state grass.”

17. Elymus canadensis. Canada wildrye. A perennial bunch grass native to North America and introduced in Montana, culms 8-15 dm tall, the spike inflorescence has a characteristic droop, and both the glumes and lemmas bear awns, often used for stabilizing soils along road cuts.

Tribe Stipeae (notice the characteristic hardened or indurated floret with a terminal awn, contrasted with papery glumes)

18. Stipa comata. Needle-and-thread grass. A perennial bunchgrass with stems less than 1 m tall, inflorescence an open panicle, characteristically hardened florets and papery glumes, the palea and flower are completely wrapped inside the lemma, the floret and awn work to disperse or bury the fruit, common on dry sites at usually lower elevations throughout Montana.

19. Stipa viridula Perennial native bunch grass, inflorescences contracted panicles, leaf sheaths are usually distinctly hairy about the throat and collar, the papery glumes contrast to the hardened floret (typical of the tribe). A dominant species in many open dry vegetation types throughout Montana, from the foothills to the prairies.

Tribe Poeae (not a distinctive group other than they don't fit into the other four tribes listed)

20. Bromus japonicus Japanese brome. Loosely bunched to single-stemmed introduced annuals, the inflorescence is usually a drooping panicle with each branch bearing several spikelets, spikelets with lemma awn straight initially to curved outward at maturity, with a hairy leaf sheaths characteristic of many annual bromes, a very common plant in disturbed areas (or with a disturbance history) throughout Montana.

21. Festuca idahoensis. Idaho fescue. A native perennial bunchgrass, leaf bunch distinctly bluish green usually, the lemmas are distinctly rounded on back and well separated from each other along the rachilla, the ligules are characteristically bilobed rendering a stair-step appearance from side-view. This species is common throughout Montana excepting the northeast, and is defines many types of native vegetation.

22. Poa compressa. Canada bluegrass. Single stemmed to loosely bunched rhizomatous perennials, inflorescence a narrow panicle, stems flattened and especially evident at nodes, stem bases decumbent and often distinctly bent at the node, native to North America but favoring disturbed sites often where water seeps.

Tribe Aveneae (notice the glumes that are larger than the included florets)

23. Koeleria macrantha. Prairie junegrass. A perennial native bunchgrass with panicles mostly contracted before and after anthesis but open during flowering, each spikelet with 2 similar florets, none of which bears an awn or only awn-tipped, paleas distinctly translucent, common to open dry sites in shrubby grassland ommunities throughout the state.

24. Phalaris arundinacea Reed canarygrass. A native rhizomatous perennial (perhaps introduced in some places) forming dense stands, the inflorescence a contracted (before or after anthesis) to open panicle (at anthesis), scale-like sterile florets occur below the single fertile one, ligule conspicous and membranous, riparian and wetland habitats at mostly low to mid-elevations throughout Montana.

syllabus