Key to Glyceria

View taxon page for Glyceria

(For a list of species in Glyceria, use the above link.)

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Spikelet ovoid; inflorescence open, branches 

spreading 

Oriented more or less perpendicularly to the axis of attachment; often, more or less horizontal.

2. Lemma tip ± flat; anthers 3 ..... G. grandis

2' Lemma tip boat-shaped; anthers 2

3. Leaf 

blade 

Expanded portion of a leaf, petal, or other structure, generally flat but sometimes rolled, cylindric, wavy, or cupped.

6–15 mm wide; anther 0.5–0.8 mm; stem 60–150 cm, 2.5–8 mm diam; lower 

glume 

In Poaceae, each of generally two sheathing bracts that are the lowermost parts of a spikelet, subtending one or more florets.

0.8–1.5 mm ..... G. elata

3' Leaf blade 2–6 mm wide; anther 0.2–0.6 mm; stem 20–130 cm, 1.5–5 mm diam; lower glume 0.4–1.2 mm ..... G. striata

1' Spikelet 

cylindric 

Elongate, with parallel sides and, at any point, round in transverse section.

; inflorescence narrow, branches 

appressed 

Parallel or nearly parallel to and often in contact with surface of origin; used to describe the disposition of hairs, leaves, pedicels, etc.

4. Lemma glabrous between barely scabrous veins ..... G. borealis

4' Lemma scabrous throughout

5. Lemma 2.5–4(4.5) mm, tip 

truncate 

Abruptly (not gradually) narrower or smaller at base or tip, as if cut straight across or nearly so.

to broadly rounded, 

crenate 

Pertaining to margins with shallow, rounded teeth, between which are usually acute sinuses (i.e., scalloped)

to 

entire 

Having margins that are continuous and smooth (i.e., without teeth, lobes, etc.).

..... G. leptostachya

5' Lemma (4)4.5–8 mm, tip 

acute 

Having a short-tapered, sharp tip, the sides convex or straight and converging at less than a right angle.

to 

acuminate 

Having a long-tapered, sharp tip, the sides concave.

, generally lobed or strongly 

dentate 

Having margins with sharp, relatively coarse teeth pointing outward, not tipward.

6. Spikelet (18)20–40 mm; 

lemma 

In Poaceae, the lower, generally larger of two sheathing bracts subtending a flower, generally ensheathing the palea (in a sterile lemma, the associated flower and sometimes palea are rudimentary or absent); with the palea and flower, comprising the floret.

(5.5)6–8 mm, tip entire, acute to acuminate; anther 1.5–3 mm ..... G. fluitans

6' Spikelet 10–23 mm; lemma 4–6 mm, tip generally lobed or irregularly dentate; anthers 0.3–1.5 mm

7. Annual or 

perennial 

Completing life cycle (germination through death) in more than two years or growing seasons, generally non-woody (at least above ground) to woody; includes perennial herbs as well as subshrubs to trees; the abbreviation 'per' only refers to perennial herb, not to the word 'perennial' alone.

 herb, tufted; 

rhizome 

1. In seed plants, stem that is often elongate, more or less horizontal, usually underground; distinguished from roots by bearing of leaves, leaf scars, axillary buds, etc. 2. In ferns, stem that is located underground, embedded in leaf litter, on rocks or in rock crevices, or on trees or tree branches, often scaly or hairy; distinguished from roots by bearing of fronds (roots rarely bear fronds), and their greater diameter.

generally absent; 

leaf 

Organ arising from a stem, generally composed of a stalk (petiole) and a flat, expanded, green, photosynthetic area (blade); distinguished from a leaflet by the presence in its axil of a bud, branch, thorn, or flower; sometimes with lateral, basal appendages (stipules); either simple (toothed, lobed, or dissected but not divided into leaflets) or compound (divided into leaflets).

blade (2)3–12 cm, 1.5–6(8) mm wide; lemma tip generally 3-lobed; 

palea 

1. In Asteraceae, a scale-like bract that subtends an individual flower on the receptacle (equal to 'chaff scale' in TJM), absent in some genera, restricted to a ring separating ray and disk flowers in most tarweed species. 2. In Poaceae, the distal, generally smaller of two sheathing bracts subtending a flower, generally two-veined and -keeled and ensheathed by the lemma; with the lemma and flower, comprising the floret.

0.2–1.5 mm >= lemma ..... G. declinata

7' Perennial herb from creeping rhizome, often mat-forming; leaf blade 20–30 cm, (3)4–13 mm wide; lemma tip entire to variously dentate-crenate; palea <= lemma ..... G. ×occidentalis

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