Flower:

Branching cluster up to 6 inches long at the top of the stem, the branches ascending to spreading at flowering, often becoming more erect in fruit. Branches are stiff and wiry, the lowest branches longest becoming shorter as they ascend the stem, with 2 or more spikelets (flower clusters) crowded near the branch tip, usually all on one side of a branch. Spikelets are short-stalked to stalkless, 5 to 9 mm (~¼ to 1/3 inch) long, slightly flattened, lance-elliptic in outline and have 2 to 6 florets; the terminal floret is typically underdeveloped and sterile.

At the base of a spikelet is a pair of bracts (glumes), both alike and near the same size, narrowly lance-shaped tapering to a pointed tip, 4 to 6 mm long, usually hairy along the keel, shorter than the group of florets, the lower glume 1-veined, the upper glume 3-veined. Florets are surrounded by a pair of bracts (lemma and palea), the lemma 5-veined, 5 to 8 mm long, hairy along the keel at least near the tip, the keel extending to an awn about 1 mm long; the palea is slightly shorter than the lemma and not awned. The sterile floret at the tip is similar to fertile florets but smaller.

Leaves and stems:

Leaves are both basal and alternately attached on the lower half of the stem, 4 to 18 inches long, 2 to 14 mm (to ~½ inch) wide, mostly flat, hairless but usually rough along the edges, and light green to dark blue-green. Stem leaves are spreading to arching, basal leaves erect to arching.

 Sheaths are hairless, smooth to slightly rough, keeled along the back, and the edges fused for at least half the sheath length (closed sheath). The ligule (membrane where the leaf joins the sheath) is thin, up to 11 mm long, often shreds at the tip, is hairless or may have a fringe of minute hairs. Nodes are smooth. Stems are hairless, erect or prostrate from the base and rising at a lower node (geniculate). Plants are clump-forming from short rhizomes.

Fruit:

Spikelets are straw-colored to brown at maturity, the florets shedding individually as each grain matures, leaving the glumes behind on the stalk. Grains (seeds) are light brown and about 3 mm long.

Notes:

Orchard Grass was introduced to North America as a forage crop over 200 years ago and is still used for hay and pasture today. It escaped cultivation and can be found in disturbed soils along roadsides, fields, forest edges, thickets, wooded slopes, banks and shores, and may creep into higher grade habitat but is not overly aggressive. Its pollen is a bane of hay fever sufferers. It is a somewhat variable species with several varieties described in its native range but they are not described in North America presumably because none are native here. They're all weeds.

Orchard Grass is distinguished by the light green to blue-green foliage, sheaths closed for at least half their length, long membranous ligule, thick spikelets each with 2 to 6 florets, the uppermost floret usually smaller and sterile, lemmas and glumes both usually fringed along the keel, lemmas short-awned, and the florets shedding individually as each grain matures, leaving the glumes behind on the stalk. The panicle may have spreading to ascending or erect branches.