1 Inflorescences spikelike branches, the
spikelets partially embedded in the
rachises
2 Spikelets (at least the terminal) subtended by 1-many stiff,
terete bristles .
3 Bristles falling with the
spikelets at maturity (the disarticulation at the
base of the
fascicles )
2 Spikelets not subtended by stiff
bristles .
4 Inflorescences of spikelike branches 1-3.7 cm long, the branch extending 2.5-4 mm beyond the attachment of the
distal spikelets
4 Inflorescences not as above.
5 Upper
florets laterally
compressed
5 Upper
florets dorsally
compressed .
6 Fertile (upper)
florets shiny and black to brown-colored when mature; the
glumes abruptly
apiculate and (internally) oily, the lower
glume bases saccate ; plants erect, arching,
climbing , or
decumbent ; [s. FL only in our flora area]
6 Plants not as above (if robust, lacking shiny black
florets and not arching or
climbing ); [collectively widespread, including s. FL].
7 Lower
glumes or lower
lemmas awned.
8 Leaves > 10× as long as wide;
ligules absent or of
hairs
8 Leaves < 8× as long as wide;
ligules present,
membranous or of
hairs .
9 Lower
glumes unawned or very shortly so; upper
glumes ciliate -margined; plants erect or basally
decumbent
9 Lower
glumes awned; upper
glumes not
ciliate -margined;
culms trailing ; plants strongly
trailing , rooting at the
nodes
7 Lower
glumes and lower
lemmas unawned.
10 Lemma margins flat,
hyaline ; lower
glumes absent or < ¼ the length of the upper
glume .
11 Subterranean inflorescences absent;
aerial inflorescences either with
digitate or subdigitate branches and
glabrous spikelets , or with elongate
rachises and conspicuously
pubescent spikelets ;
spikelets of the
aerial inflorescences fertile;
spikelets glabrous ,
ciliate , or
pubescent ; leaves various (often not as above); [collectively widespread]
12 Inflorescence a narrow
panicle with the branches strongly
ascending to
appressed ;
spikelets ellipsoid to
obovoid ; [of Coastal Plain pinelands]
12 Inflorescence either a
panicle with
digitate or subdigitate clusters of spikelike branches or a broad
panicle with widely
divergent branches; [widespread]
10 Lemma margins not
hyaline , frequently
involute ; lower
glumes various (absent, < ¼ the length, to longer than the upper
glume ).
13 Spikelets subtended by a cuplike
callus
13 Spikelets not subtended by a cuplike
callus .
14 Leaves primarily lacking
ligules (at least the upper, and often all, leaves without
ligules , if
vestigial ligules present, these of
hairs )
14 Leaves with
ligules , these either
membranous or of
hairs .
15 Lower (
sterile )
palea indurate and expanding the
spikelet at maturity, as long as the lower (
sterile )
lemma ; lower and upper
florets standing apart from one another at maturity; outer surface of the upper (fertile)
palea with compound
papillae
15 Lower (
sterile )
palea membranous , not expanding the
spikelet at maturity, usually shorter than lower (
sterile )
lemma , or absent; lower and upper
florets closely
appressed at maturity; outer surface of the upper (fertile)
palea lacking compound
papillae .
16 Inflorescence of 1-sided, spikelike primary branches.
17 Spikelets with lower
lemmas (and lower
glumes , if present) adjacent to the branch
axes .
17 Spikelets with upper
lemmas (and upper
glumes , if present) adjacent or
appressed to the branch
axes .
19 Both
glumes absent from all or most
spikelets
19 Upper or both
glumes present on all
spikelets .
20 Lower
glumes usually absent; upper
lemmas smooth to slightly
rugose
20 Lower
glumes present; upper
lemmas rugose and
verrucose
16 Inflorescence either
paniculate with well-developed secondary
branchlets or if the primary branches spikelike, then the
spikelets not borne in a 1-sided arrangement on the
spicate branches.
21 Inflorescences dense, the
spikelets obscuring most of the internal branches
21 Inflorescences open
panicles , or if narrowed, all or nearly all the
panicle branches readily visible.
22 First
glume 5-7.5 mm long, nearly as long as
sterile lemma ; fertile
lemma 1/3 length of
sterile lemma ;
rachilla prolonged between the
florets
22 First
glume shorter, or if this long, then at most 3/4 length of
sterile lemma ; fertile
lemma > ½ the length of the
sterile lemma ;
rachilla not prolonged between the
florets .
23 Plant developing a terminal (“spring”)
inflorescence usually before mid-summer, followed by
lateral (“
autumnal ”)
inflorescences from lower, mid, and/or upper
nodes , these often included or hidden among the
fascicles of smaller “
autumnal ” leaves; often developing a
rosette of overwintering
basal leaves
23 Plant developing a terminal
inflorescence usually after mid-summer, the
lateral inflorescences , when present, from the upper
nodes , usually appearing at the same time as the terminal
panicle , and not hidden by dense
fascicles of smaller leaves; plants lacking a
rosette of overwintering
basal leaves.
25 Panicle < 2 cm wide at maturity.
26 Spikelets > 4.5 mm long; first
glume > 2.4 mm long;
ligule 4-6 mm long; [of coastal
dunes ]
26 Spikelets < 4 mm long; first
glume < 2.1 mm long;
ligule < 2 mm long; [not of coastal
dunes ].
27 Blades involute , 1.5-4 mm wide;
culms wiry
27 Blades flat, the larger 6-20 mm wide;
culms stout.
28 Panicles constricted , 0.3-1.6 cm wide;
spikelets subsessile to short-
pediceled ; summit of fertile
palea not enclosed by fertile
lemma
28 Panicles > 1 cm wide;
spikelets short to long-
pedicelled ; summit of fertile
palea enclosed by fertile
lemma
25 Panicle > 2 cm wide at maturity.
29 Fertile
lemmas rugose with cross-
venation between the main parallel veins
29 Fertile
lemmas not
rugose .
30 Lower primary
panicle branches in
whorls of 4-7 at the
nodes , stiffly spreading,
naked on the
proximal ½, the
axils strongly
pilose ; lower
culm internodes appressed papillose -
pubescent ; first
glume acuminate , ½ as long as
spikelet ; fertile
lemma chestnut brown at maturity
30 Plants without the above combination of characters.
31 Plants from a cluster of
fibrous roots , without
rhizomes or hard knotty
crowns , annual
31 Plants with
rhizomes or hard knotty
crowns , perennial.
32 Plants with hard
crowns , lacking
rhizomes ; fertile
lemma 1.2-1.6 mm long
32 Plants with
rhizomes ; fertile
lemma 1.6-4 mm long.
33 Rhizomes about 1 cm thick with
pubescent scale-like leaves ; lower portion of
culm hard, nearly
woody
34 First
glume truncate apically
35 Culms slightly
compressed below;
ligules 0.5 mm long or less;
spikelet pedicels appressed , the
spikelets subsecund, usually some obliquely bent above the first
glume ; fertile
lemma 1.8-2.2 mm long
35 Culms terete ;
ligules 1-6 mm long; at least some
spikelet pedicels spreading,
spikelets not at all
secund , essentially straight; fertile
lemma 2-4 mm long
1 Spikelets 2-flowered, often dorsally
compressed , falling
entire at maturity (the
abscission below the
glumes ), the upper
floret usually
bisexual , the lower one male or
sterile ; [tribe
Paniceae ]
2 Lemma margins hyaline , flat; lower
glumes various (absent, < ¼ the length, or longer than the upper
glume )
2 Lemma margins not
hyaline , frequently
involute ; lower
glumes absent or < ¼ the length of the upper
glume .
3 Spikelets with lower
lemmas (and lower
glumes , if present) adjacent to the branch
axes .
3 Spikelets with upper
lemmas (and upper
glumes , if present) adjacent or
appressed to the branch
axes .
5 Both
glumes absent from all or most
spikelets
5 Upper or both
glumes present on all
spikelets .
6 Lower
glumes usually absent; upper
lemmas smooth to slightly
rugose
6 Lower
glumes present; upper
lemmas rugose and
verrucose
1 Spikelets 1-, 2-, or many-flowered, usually
terete or somewhat laterally
compressed , either abscising at maturing above the
glumes or if 2-flowered then both
florets bisexual , or the upper
sterile ; [tribes
Cynodonteae and
Zoysieae ]
7 Spikes normally solitary (rarely 2),
divergent at the summit of the
culm ; second
glume with a
recurved spine arising from the back; fresh plants aromatic with a citrus odor; [tribe
Cynodonteae ; subtribe “
incertae sedis ”]
7 Spikes normally 2 or more,
alternate ,
digitate , subdigitate, or
verticillate along the main
inflorescence axis ; second
glume lacking a
recurved spine ; fresh plants not aromatic with a citrus odor.
8 Spikes arranged along the central
inflorescence axis alternately, solitary at each
node or
inflorescences consisting of a solitary spikelike
raceme (
Zoysia ).
9 Spikelets with 1
bisexual floret , sometimes also accompanied by modified male,
sterile , or
rudimentary florets above the fertile
floret .
10 Spikelets with modified male,
sterile , or
rudimentary florets above the fertile
floret ; [plants of uplands]; [tribe
Cynodonteae ; subtribe
Boutelouinae ]
10 Spikelets lacking any modified
florets ; [tribe
Zoysieae ; subtribes
Sporobolinae and
Zoysiinae ]
11 Spikelets with 1 fertile
floret accompanied by a
sterile , reduced
floret ;
inflorescence of 1-many
spike -like
panicles (the branches
appressed to strongly
divergent ); [plants of wetlands, primarily
saline and coastal]; [tribe
Zoysieae ; subtribe
Sporobolinae ]
11 Spikelets with 1 solitary fertile
floret ;
inflorescence of solitary
spike -like
racemes ; [
waifs or uncommon non-native turf grasses of disturbed areas]; [tribe
Zoysieae ; subtribe
Zoysiinae ]
9 Spikelets with 2 or more
bisexual florets (sometimes also with additional reduced
florets ); [tribe
Cynodonteae ; subtribe
Eleusininae ].
12 Ligules 4-8 (-15) mm long,
acute to
attenuate ,
entire (
lacerate only by tearing)
12 Ligules 0.3-5.4 mm long,
truncate to
obtuse ,
erose or
entire .
13 Lemmas 3-veined;
ligule (0.2-) 0.5-5.5 (-7.0) mm long;
apex erose or
entire
13 Lemmas 5-veined;
ligule 0.8-2.2 mm long,
apex erose
8 Spikes arranged along the central
inflorescence axis in a
digitate , subdigitate, or
verticillate manner, all or most
nodes with 2 or more
spikes ; [tribe
Cynodonteae ].
14 Spikelets with 1 fertile
floret (there may also be 1 or more
sterile florets ); [tribe
Cynodonteae ; subtribe
Eleusininae ].
16 Lowest
lemmas awned (rarely unawned); upper
glumes acute to
acuminate ,
mucronate or short-awned
16 Lowest
lemmas unawned (or with an
awn to 1.2 mm long); upper
glumes truncate or
bilobed , sometimes short-awned from between the
lobes
14 Spikelets with 2 or more fertile
florets .
17 Spikes to 7 cm long, terminating in a point (the
spikes acuminate ); [tribe
Cynodonteae ; subtribe “
incertae sedis ”]
17 Spikes to 22 cm long, terminating in a functional or
rudimentary spikelet (the
spikes acute to
obtuse ); [tribe
Cynodonteae ; subtribe
Eleusininae ].
18 Lemmas pubescent , at least towards the
base .