The wheatgrass tribe Triticeae

Be sure to run all of your grass samples through the keys in the Grasses of Montana so that you can develop an association of a taxonomic group (tribe, genus, species) with its diagnostic traits or morphologies.

1. Lolium multiflorum (not a wheatgrass but Lolium is superficially similar to them). An annual to biennial or short-lived bunchgrass, inflorescence a terminal two-sided spike but with spikelets attached edge-wise, mostly from lawn and pasture mixes and escaping in disturbed settings.

2. Agropyron intermedium var. trichophorum. A perennial rhizomatous and bunchgrass commonly of roadside habitats, very similar to Ag. intermedium except for the very hairy spikelets.

3. Agropyron trachycaulum (Elymus trachycaulus). A perennial bunchgrass with spikelets having broad and long glumes that are often as nearly as long as the entire spikelet, a leafy Agropyron not to be confused with Ag. repens because this species is a bunchgrass and the lemmas are mostly awnless (excepting a form with very long awns), an extremely variable species and widespread in Montana from the prairie to the subalpine, inhabiting disturbed sites such as roadsides, trail sides, loose gravel or talus, dry stream beds.

4. Eremopyrum triticeum. Annual bunchgrass with a terminal spike that becomes hardened and burr-like and disperses as a unit (in contrast to Ag. cristatum), of dry sandy or gravelly recently disturbed soils.

5. Secale cereale. An annual bunchgrass with spikelet having small narrow glumes and lemma margins lined with conspicuous pectinate hairs, cultivated at northern latitudes relative to other cereal crop species and often escaping cultivation and forming dense stands in disturbed settings or planted road side.

6. Aegilops cylindrica. An annual bunchgrass with spikelets nearly or entirely embedded within the rachis, the unit of disarticulation is a spikelet and adjacent rachis internode, the glumes are broad and with an acentric midrib like that of Triticum.

7. Elymus glaucus. A perennial bunchgrass, a leafy Elymus not to be confused with Ag. repens because of its bunched habit and montane habitat, the glumes are broadest above the base and each has 3-5 distinct veins, the lemmas have long awns, in dry meadows or open forests in the mountains.

8. Elymus elymoides (Sitanion hysterix). A perennial bunchgrass, inflorescence distinctively purplish during mid summer and with long awns, the inflorescence rachis disarticulates at maturity, awns of the glumes and lemmas are long and the glumes often become divided into two or more awn-like segments, one of the pair of spikelets at a node bears 0-2 seed-bearing florets whereas the other bears typically 2-5 fertile florets per spikelet, in dry open shrub-grass settings, also on disturbed or heavily used sites and along roadsides, hybridizes readily with other wheatgrass species. Possibly confused with Hordeum jubatum.

9. Elymus cinereus (Leymus cinereus). A perennial that forms very large bunches often over 1 m in diameter and with stems usually well over 1.5 m tall, inflorescence typically with 3 spikelets per node and more than one floret per spikelet, open dry settings from the sagebrush steppe to low elevation mountain meadows and presumably where water seeps. The large size of this grass is the most conspicuous vegetative diagnostic character.

10. Elymus junceus (Psathyrostachys juncea). A perennial bunchgrass 5-10 dm tall, the bunches several inches in diameter, leaves 2-7 mm wide but often withering entirely by mid summer, introduced for forage and reclamation. The inflorescence is somewhat similar to that of Elymus cinereus but this species is not as large in diameter and height and the inflorescence is more slender (e.g., exactly two spikelets per node) and the lemmas seem to be a bit more evenly hairy.

11. Taeniatherum caput-madusae. An annual bunchgrass forming dense stands or mats, inflorescences have with two spikelets per node (like Elymus) but one floret per spikelet (like Hordeum), the heads do not shatter (disarticulation is above the glumes), a colonizer of disturbed open dry sites.

12. Hordeum brachyantherum. A perennial bunchgrass similar to Hordeum jubatum but with shorter awns, erect spikes, and inhabiting a meadow and riparian settings in the mountains.

13. Hordeum leporinum. An annual bunchgrass often forming dense stands where it colonizes recently disturbed settings, all three of the spikelets at a node have well developed florets although the two lateral spikelets produce only staminate (non-seed bearing) florets.

Some other common wheatgrasses (including their "genomic" names when different from the traditionally recognized scienctific name):

· Agropyron smithii (Pascopyrum smithii). Rhizomatous perennial with blue-green (glaucous) leaves and stems like those of Ag. dasystachyum but with subulate glumes broadest at the base and single-veined.

· Elymus flavescens (Leymus flavescens). A native rhizomatous perennial with lemmas that are very strongly hairy.

· Elymus virginicus. Similar to blue wildrye but with glumes bases hardened, curved, and bony in texture.

syllabus