Three spikelets at each node. Spikelets one-flowered, central one only fertile.
Hordeum spp.
4
Spike one-sided; spikelets one-flowered.
Nardus stricta
Spike not one-sided; spikelets several-flowered.
5
5
Spikelet placed edgewise; 1 glume only.
6
Spikelet placed sideways on; 2 glumes.
Agropyron repens
(Wheat 3 or more large florets and broad glumes,lemmas usually awnless, and Rye with two large floretsand narrow glumes, lemmas always awned, come here)
6
Lemmas awnless.
Lolium perenne
Lemmas awned.
Lolium multiflorum
7
Spikelets usually many-flowered (4 or more);glumes short, not hiding florets.
8
Spikelets few-flowered (2–5 usually); glumes long,concealing at least the lower florets.
19
Spikelets one-flowered; glumes long, concealingfloret.
23
8
Panicle branches mainly spreading.
9
Panicle branches very short, not spreading, so thatinflorescence looks more like spike. Sterileskeleton spikelets present as well as fertile.
Cynosurus cristatus
9
Lemmas with awn on back.
10
Lemmas awnless or with awn on tip.
11
10
Lemmas rounded, spikelet oval.
Bromus mollis & related species
Lemmas keeled, spikelet triangular.
Bromus sterilis & related species
11
Lemmas with rounded back.
12
Lemmas keeled on back.
16
12
Lemmas very blunt.
13
Lemmas bluntly or sharply pointed or shortlyawned.
14
13
Spikelets long, cylindrical.
Glyceria fluitans
Spikelets short, rounded-triangular.
Briza media
14
Panicle purple, usually long and slender, stigmaand anthers dark purple.
Molinia caerulea
Panicle green, becoming brown or yellowish.Stigma and anthers pale.
15
15
Panicle and florets small.
Festuca ovina & F. rubra
Panicle and florets larger, two branches at mostnodes, with 1 or 2 spikelets on smaller branch,lemmas bluntly pointed.
Festuea pratensis
Panicle very large, 3 or more spikelets on smallerbranch, lemmas with awn-point.
Festuca arundinacea
16
Lemmas straight, bluntly pointed.
17
Lemmas curved, with awn point, panicle largewith dense clumps of spikelets.
Dactylis glomerata
17
Panicle small, no “web.”
Poa annua
Panicle larger, “web” of cottony hairs at base oflemma.
18
18
Spikelets rather small, panicle open, light andfeathery in appearance.
Poa trivialis
Spikelets slightly larger, panicle closer, denser andheavier in appearance.
Poa pratensis
19
Panicle branches mainly spreading. Spikelet erect.
20
Panicle branches short, not spreading. Spikelet ofone shiny fertile floret and two sterile brownhairy awned lemmas.
Anthoxanthum odoratum
20
Spikelets two-flowered, one fertile, one male only.
21
Spikelets with two or more fertile florets.
22
21
Spikelets fairly large, lower floret male withprominent bent awn, upper floret fertile.
Arrhenatherum elatius
Spikelets small, lower floret fertile, upper floretmale with small fish-hook awn.
Holcus lanatus
(Holcus mollis similar but with more prominent bent awn)
22
Panicle rather small, closing in fruit, yellow,spikelets 2–5 flowered.
Trisetum flavescens
(Helictotrichon spp. with
