Grasses in the
area between the Museum of the
The following grass species dominate the human landscape in
Tribe Triticeae (wheat grasses, characterized by an inflorescence that is a bilateral terminal spike)
1. Agropyron repens (Elytrigia repens). Quackgrass. An introduced rhizomatous perennial. The leaf blades in fresh condition are mostly flat, lax, green, and not rigid. This species is similar to Agropyron intermedium but differs in having thin pointed glumes and lemmas usually bearing an awn (this last photo compares quackgrass with intermediate wheatgrass, which has no awns). Common in somewhat moist disturbed settings.
2. Hordeum jubatum. Foxtail
barley. A native perennial bunch grass, pioneering and widespread throughout
western
3. Hordeum vulgare. Barley. Annual bunchgrass, rarely escaping cultivation. Compare 2 and 6-row barley and note the different construction of the 3 spikelets per node and 1 floret per spikelet. In 2-row barley, the two lateral spikelets are sterile and pedicellate and the central one is sessile and fertile. In 6-row, the two lateral spikelets are fertile and sessile, just like the central spikelet. Only 2-row barley has the characteristic spikelet arrangement of the genus Hordeum, whereas 6-row cultivars deviate from the norm via a single gene mutation. Some 6-row cultivars have lemma awns transformed into hoods.
4. Triticum
aestivum. Wheat. Cultivated annual bunchgrass,
occasionally escaping but not persisting. This species is the most cultivated
crop in
Tribe Poeae (not a very distinctive group, and characterized by not fitting the characteristics of the other more distinctive cool season grass tribes)
5. Bromus inermis. Smooth brome. An introduced rhizomatous perennial, the inflorescence is an open panicle, and the spikelets bear relatively few awns (sometimes none), the leaf sheath is closed (characteristic of Bromus), the leaf blade has an imprinted "W", the palea (pictured here is Bromus japonicus) is attached to grain (a characteristic of the genus Bromus), forming extensive dense stands along roadsides, pastures, and disturbed areas with moist soil, also forming open stands in montane unstory habitats.
6. Poa pratensis. Kentucky bluegrass. A mostly introduced sod-forming perennial, inflorescences of open panicles, spikelets with no awns (characteristics of Poa), leaf blades are folded along midrib (and the midrib is lined on either side by a distinctive row of cells) and have a distinctive prow tip (characteristic of Poa), lemmas bear cobwebby hairs (characteristic of a subset of Poa species), rhizomes and tillers well developed, a colonizer of both disturbed and open native vegetation.
Tribe Aveneae (notice the glumes that are larger than the florets that the florets they enclose)
7. Phelum pratense. timothy.
Perennial weakly bunched
grass, inflorescences of dense cylindrical spikes
with disarticulation above the glumes (the one on the left), spikelets
with a single floret and glumes bearing short stout awns, ligule
well developed and surrounding much of the stem.
8. Alopecurus arundinaceus. Garrison
creeping foxtail. Introduced rhizomatous perennials, inflorescences
of dense cylindrical spikes with disarticulation
below the glumes,
the spike commonly turns dark or
black as the spikelets disarticulate by the end of the summer, spikelets
with awnless
glumes and lemmas bearing a short awn that does not exceed the length of
the glumes,
inhabiting riparian
or wetland sites.
9. Agrostis stolonifera. Redtop or Carpet bentgrass. Introduced strongly rhizomatous perennial sod grass often forming dense stands in moist settings. The stems may root at nodes. The inflorescence is an open panicle where spikelets are borne along secondary branches even close to the main rachis (compare this with the "naked" secondary inflorescence branches of Agrostis scabra). The spikelets of Agrostis are distinctive in having two equal-sized but very small glumes each with scabrous midribs.
10. Avena fatua. Wild oats. An introduced bunched annual, colonizing especially along roadsides and cultivated fields. The inflorescence is a diffuse panicle. The large glumes that enclose the florets, and awns that arise from the back of the lemma are distinctive characteristics of oatgrasses.
11. Calamagrostis stricta. Northern reedgrass. Native perennial bunchgrass, often loosely bunched with slender rhizomes and commonly forming dense stands in moist settings (e.g., ditches along roads, wet meadows). The inflorescence is a contracted panicle. Note the single floret per spikelet and callus hairs that are more than one-half the length of lemma. These callus hairs obscure the lemma awn. [Compare with Calamagrostis canadensis].
Tribe Meliceae (notice the ribbed lemmas, closed leave sheaths, plants lacking hairs on the stems, leaves, inflorescences, and spikelets)
12. Glyceria grandis. American mannagrass. Single-stemmed rhizomatous perennials forming dense stands, inflorescence of open panicles, the lower branches of which often droop, leaf sheaths closed and the lemma veins are many, prominent, and parallel, inhabiting streamsides, road ditches, wet meadows, and edges of lakes.
