Generally, these are C4 grasses with non-panicoid spikelets (sterile
florets - if any, above the fertile ones) and ligules of either a fringe
of hairs or sometimes membranaceus. Inflorescences are some type
of panicle (or rarely a one-sided spike) - either open or made up of one-sided,
spike-like segments. Often 2 prominent keels on palea.
Most common genera with most helpful field characteristics:
1) Spikelets with a single fertile floret.
Chloris (including Eustachys) - Type genus,
one sided spike, florets brown, digitate racemes (rarely with 2nd fertile
floret)
Cynodon - Digitate racemes, no awns.
Gymnopogon - long digitate racemes, short lvs., awned
spikelets.
Muhlenbergia- Panicle - like Sporobolus - very open and
wispy, - but with a pointed lemma.
Spartina - Alternate racemes - tough leaves
Sporobolus - Panicle - like Muhlenbergia but with
a blunt lemma, one floret per spikelet. Can be more of a dominant
than Aristida in longleaf pine woods. S. junceus has
no cottony hairs in axils, leaves look like wire-grass. S. virginicus
looks like Distichlis vegetatively.
Zoysia - Usually only after habitation, tiny plants, tiny
panicle.
2) Spikelets with more than one fertile floret.
Ctenium - Single raceme (one-sided spike) with pairs of
spikelets.
Dactyloctenium - Digitate racemes at right angle to stem
Eleusine - digitate racemes
Eragrostis - ligule of hairs, lemma not toothed, very
regular flat straight-sided spikelets.
Distichlis - distichous lvs, halophile.
Leptochloa - membranaceus ligules - green fls - appears
to be many spike-like racemes in panicle, lemmas toothed at tip.
Neyraudia - big reed like Phragmites but more of a clumper,
persistent hard and shiny leaf sheaths, wet or dry areas, inflorescence
much bigger but smaller flowers than Phragmites, tuft of hairs around ligule,
curved awns, looks like it has 3 “glumes.”
Tridens - ligules membranaceus - reddish fls, - lemma
toothed
Triplasis - ligule of hairs, lemmas toothed (W), palea
nerve - fls reddish
Uniola - Sea oats