2 Ligule (1.5-) 2-5 mm long;
sheaths glabrous to variously
pubescent ;
internodes glabrous or
pubescent ;
nodes glabrous , or
bearded with
ascending , spreading, or tangled
hairs ; leaves 3-10 cm long, 3-10 mm wide;
spikelets 0.8-1.9 mm long
3 Basal leaves
rosette -forming, usually much smaller than the
culm leaves, not matted or cushion-forming;
culms branching at the mid and upper
nodes in age.
4 Blades of mid-
culm leaves typically long and
acuminate ,
linear or narrowly
lanceolate , usually 10-20× as long as wide, only 2-5 mm wide when < 8 cm long.
5 Vernal leaf
blades 9-20 cm long, the larger usually 5-8 mm wide, becoming longer upwards on the
culm , (weakly-) strongly
scabrous on the
adaxial surface;
spikelets sparsely
pubescent to
glabrous
5 Vernal leaf
blades to 11(14) cm long, those on the upper
culm smaller or similar in size to those below, the
adaxial surface not
scabrous except sometimes on the
margins (or
scabrous in D. neuranthum with leaves no more than 5 mm wide and
spikelets moderately
glandular papillose -
pubescent ).
6 Spikelets (
glandular -)
papillose -
pubescent ;
blades 1-3 (-5) mm wide; first
glume 0.8-1.0 mm long;
culms to 4 dm tall
6 Spikelets glabrous ;
blades 3-8 mm wide; first
glume 0.3-1.1 mm long;
culms to 10 dm tall.
7 Leaves 3-8 mm wide;
panicle (8-) 20-40 mm wide; first
glume 0.6-1.1 mm long, blunt to
acute
7 Leaves 3-5.5 mm wide;
panicle 2-5 mm wide; first
glume 0.3-0.4 mm long,
truncate to
obtuse
4 Blades of mid-
culm leaves
lanceolate , mostly 10× or less as long as wide, usually 7 mm or more wide when as much as 8 cm long.
8 Spikelets elliptic ,
oblong , or
obovate ; lower
culm blades 3-12 (-15) mm wide, thin, tapered to the
base ; plants often freely branching in age, becoming top-heavy with a mass of
fascicled , reduced leafy branches and
inflorescences
8 Spikelets broadly
elliptic to suborbicular; lower
culm blades 6-30 mm wide, broad and
cordate to subcordate at the
base ; plants sparingly branched in age, not becoming top-heavy with
fascicled , reduced leafy branches and
inflorescences .
9 Leaf
blades not noticeably thick;
ligules ciliate , to 0.8 mm long;
spikelets 1.8-2.6 mm long,
elliptic ,
obtuse to subacute; first
glumes 0.5-1.0 mm long
9 Leaf
blades thickish;
ligule obsolete or with
cilia < 0.8 mm long;
spikelets 0.9-1.9 mm long,
obovoid to
spherical , rounded; first
glumes 0.2-0.8 mm long.
10 Spikelets 0.9-1.2 mm long; longer
blades 6-8 cm long, erect to erect-
ascending
10 Spikelets 1.2-1.9 mm long; longer
blades 8-20 cm long,
ascending or the uppermost erect.
11 Mid-
culm blades to 25 cm long, 14-30 mm wide, the uppermost 10-15+ cm long;
vernal panicles to 20 cm long, often less than half as wide as long;
spikelets 1.3-1.6 (-1.7)
11 Mid-
culm blades to 10 cm long, 5-11 (-14) mm wide, the uppermost 3-9 cm long;
vernal panicles to 14 cm long, usually more than half as wide as long;
spikelets (1.4-) 1.5-1.8 mm long
3 Basal leaves similar to or larger than the mid and upper
culm leaves, often matted or cushion-forming;
culms branching at the
base (also at mid and upper
nodes in
D. chamaelonche vars. and
D. dichotomum var.
glabrifolium ).
12 Longer
blades > 6 cm; if only 6 cm, then
sheaths retrorsely long-
pilose (
D. laxiflorum ).
13 Spikelets 1.2-1.5 mm long,
glabrous
13 Spikelets 1.7-2.3 (-2.8) mm long,
pubescent .
14 Longer
blades 6-18 cm long by 7-12 mm wide;
sheaths conspicuously
retrorsely long-
pilose ;
nodes bearded with
retrorse or spreading
hairs ;
spikelets (1.4-) 1.9-2.3 (-2.5) mm long
14 Longer
blades 10-35 cm long by 2-6 mm wide;
sheaths glabrous to variously
pilose , but not conspicuously
retrorsely long-
pilose ;
nodes variously
pubescent to
glabrate ;
spikelets 1.7-2.3 (-2.8) mm long.
15 Fresh plants light green to blue-green; leaf
sheaths usually
pilose ;
ligule of largest
culm leaves 3-6× as wide as long;
culm blades to 35 cm long, usually
pilose on the upper surface
15 Fresh plants darker green; leaf
sheaths usually
glabrous ;
ligule of largest
culm leaves usually > 6× as wide as long;
culm blades to 15 cm long, usually
glabrate to
glabrous on the upper surface
16 Blades 1-3 mm wide,
glabrous , eciliate or basally
ciliate ;
spikelets 0.9-1.4 mm long.
17 Spikelets pubescent , 1.2-1.4 mm long;
blades involute , often
falcate , 2.5-6 cm long; [
endemic to c. and s. FL scrub]
17 Spikelets glabrous , 0.9-1.2 mm long;
blades flat, not
falcate , 1.5-4 (-5) cm long; [wet sites, VA s. to FL, w. to e. LA]
16 Blades 3-8 mm wide;
spikelets 1.1-2.1 mm long (if < 1.5 mm, then
blades either
pubescent on one or both surfaces or
ciliate to the
apex ).
18 Spikelets pubescent , 1.5-2.1 mm long;
blade surfaces
glabrous
19 Blades glabrous , or sparsely
pilose only near the
adaxial base ;
spikelets 1.4-2.1 mm long
19 Blades pilose , at least abaxially;
spikelets 1.1-1.6 mm long
1 Internodes glabrous (sometimes lowest
internodes sparsely to moderately
pubescent ).
2 Ligule (1.5-) 2-5 mm long;
sheaths glabrous to variously
pubescent , but not spreading short-
pilose ;
nodes glabrous or
pubescent , but not
bearded ; leaves 4-11 cm long, 4-8 mm wide.
3 Leaf
blade basal cilia usually conspicuous; larger
vernal blades 6-10 cm by 6-10 mm;
internodes , especially lower, sometimes
pilose ;
spikelets obovoid ; plant often yellowish-green (orange-brown in age)
3 Leaf
blade basal cilia usually inconspicuous or absent; larger
vernal blades 2.5-10 cm long, 2-9 mm wide; all
internodes glabrous (rarely the lowest sparsely
pilose );
spikelets ellipsoid ; plant often green to purplish.
4 Spikelets (0.9-) 1.1-1.5 mm long, moderately densely to densely
puberulent , most
hairs < 0.1 mm long;
panicles 3-8 cm long, usually more than ½ as wide as long; larger
blades 2.5-8 cm long
4 Spikelets (1.3-) 1.4-1.9 mm long, (
glabrous -) sparsely to moderately
pubescent , most
hairs > 0.1 mm long;
panicles 4-12 cm long, usually less than ½ as wide as long; larger
blades 7-10 cm long
5 Peduncle ,
panicle axis , and/or
sheaths of
vernal culms puberulent with
hairs 0.1 mm long, sometimes also
pubescent with longer
hairs , but never grayish-
villous ; larger leaf
blades 2-7 cm long, 2-7 mm wide.
6 Spikelets 0.8-1.1 mm long; mid-
culm leaf
blades 2-4.5 cm long, 2-5 mm wide;
sheaths sparsely
puberulent to
glabrous , lacking
papillose -based longer
hairs
6 Spikelets 1.1-1.7 mm long; mid-
culm leaf
blades generally 3-7 cm long and 3-7 mm wide;
sheaths with some
papillose -based
hairs 2 mm or more long.
7 Larger mid-
culm leaf
blades 4-7 cm long, 4-7 mm wide,
glabrous to sparsely
pubescent adaxially;
ligule 1-5 mm long;
spikelets 1.1-1.5 mm long
7 Larger mid-
culm leaf
blades 3-6 cm long, 3-5 mm wide, long-
pilose adaxially;
ligule often with a ring of
hairs < 1 mm and scattered longer
hairs to 4 mm;
spikelets 1.3-1.7 mm long
5 Peduncle ,
panicle axis , and
sheaths of
vernal culms glabrous , or
pilose , or grayish-
villous with some shorter
hairs 0.2-0.5 mm long, but not
puberulent with
hairs 0.1 mm long; larger
blades 4-20 cm long, 4-12 mm wide.
8 Culms > 100 cm long;
node pubescence densely
retrorse ; larger
blades 12-20 cm long;
vernal spikelets 1.9-2.3 mm long, nearly 2× as long as wide;
autumnal spikelets 2.2-2.5 mm long, > 2× as long as wide
8 Culms < 100 cm long (-rarely longer);
node pubescence various; larger
blades 4-12 cm long, < 15 × as long as wide;
spikelets (1.0-) 1.1-2.0 mm long, less than 2× as long as wide, rounded to blunt.
9 Sheaths and
internodes of
vernal culms gray-
villous with a dense, tangled, or matted mixture of slender
hairs 2-4 mm long, variously
ascending , spreading, and
retrorse ,
papillose or non-
papillose , often with shorter
hairs beneath; leaf
blades velvety-
pubescent on
abaxial surface, the
margins ciliate (or appearing
ciliate ) for half or more their length.
10 Plants drying light green to yellow-green;
culms usually < 60 cm long; lower
internodes rarely more than 1.3 mm in diameter;
panicles usually < 8 cm long; primary branching at most
nodes before maturation of
vernal panicle , longer branches often exceeding the
culm
10 Plants drying olive-green, sometimes purplish;
culms usually > 60 cm long; lower
internodes usually > 2 mm in diameter;
panicles usually 9-11 cm long; primary branching sparingly from middle
nodes after maturation of
vernal panicle , longer branches not exceeding
culm
9 Sheaths and
internodes of
vernal culms puberulent ,
pubescent or
papillose -
pilose to
hispid with
ascending straight
hairs , but never grayish-
villous ; leaf
blades glabrous to variously
pilose abaxially, but not velvety-
pubescent , the
margins eciliate or
ciliate only below the middle.
11 Spikelets 0.8-1.1 mm long;
blades 2-4.5 cm long, 2-5 mm wide
11 Spikelets 1.1-2.0 mm long;
blades 3-12 cm long, 3-12 mm wide.
12 Peduncle ,
panicle axis , and often middle and upper
internodes glabrous ;
sheaths lacking
hairs or
papillae , at least near mid-length
13 Leaf
blades 5-12 cm long, 6-12 mm wide;
spikelets 1.5-2.0 mm long;
peduncle ,
panicle axis , and
sheaths variously
pilose , but lacking
puberulent hairs 0.1 mm long
13 Leaf
blades 3-7 cm long, 3-7 mm wide;
spikelets 1.1-1.7 mm long;
puberulent hairs 0.1 mm long often present on
peduncle ,
panicle axis , or
sheaths .
14 Larger mid-
culm leaf
blades 4-7 cm long, 4-7 mm wide,
glabrous to sparsely
pubescent adaxially;
ligule 1-5 mm long, the
hairs of one series;
spikelets 1.1-1.5 mm long
14 Larger mid-
culm leaf
blades 3-6 cm long, 3-5 mm wide, long-
pilose adaxially;
ligule often with a short series of
hairs <1 mm long in front of a series with
hairs to 4 mm long;
spikelets 1.3-1.7 mm long
3 Ligule an eciliate membrane; fertile
lemma and
palea densely
papillose at 20×; leaves 3.5-7 cm long by 3-6 mm wide;
culms weak, usually
sprawling over other
vegetation
3 Ligule ciliate ; fertile
lemma and
palea smooth, with few or no
papillae ; leaves either 1.5-4 (-5) cm long by 1-5 mm wide, or 5-12 cm long by 3-15 mm wide.
4 Spikelets 0.9-1.4 mm long;
vernal cauline blades 1.5-4 (-5) cm long and 1-5 mm wide;
internodes or
sheaths glabrous or
pubescent .
5 Spikelets 0.9-1.2 (-1.4) mm long;
sheaths glabrous ;
vernal cauline blades 1-2 (-3) mm wide;
ligule < 1 mm long;
node beard hairs erect and often only partially encircling the
node ;
internodes glabrous or
puberulent
4 Spikelets 1.4-2.3 mm long;
vernal cauline blades 5-12 cm long and 3-15 mm wide;
internodes and
sheaths glabrous .
6 Spikelets 1.8-2.3 mm long; first
glume 0.6-1.1 mm long; fertile
lemma 0.8-1.0 mm wide; widest
vernal blades 3-8 (-10) mm wide;
nodes , often only the lower, usually sparsely to moderately
bearded with
retrorse hairs
6 Spikelets 1.4-1.9 mm long; first
glume 0.3-0.6 (-0.7) mm long; fertile
lemma 0.6-0.8 mm wide; widest
vernal blades 7-15 mm wide; usually all
nodes densely
bearded with
retrorse hairs
7 Spikelets 1.2-1.4 mm long;
sheaths spreading-
pilose ;
vernal cauline blades 1-4 cm long and 2-5 mm wide;
ligule 1-2 mm long
7 Spikelets 1.4-2.8 mm long;
sheaths glabrous to
pilose ;
vernal cauline blades 5-15 cm long and 5-15 mm wide;
ligule ≤ 1 mm long.
8 Culms (55-) 70-140 cm long; lowest
internodes moderately to densely
villous ;
vernal cauline leaves 6-15;
blades glabrous except for
basal cilia ;
spikelets 1.8-2.2 mm long,
obovoid to broadly
ellipsoid , rounded to blunt
8 Culms 30-110 cm long; lowest
internodes glabrous to sparsely hairy;
vernal cauline leaves 3-7;
spikelets 1.4-2.8 mm long,
elliptic to lance-
ovate , blunt to
acute .
9 Usually all
culm nodes bearded ;
internodes glabrous , or middle and upper
internodes and
peduncle sparsely to moderately spreading short-hairy, sometimes also
glandular ; upper as well as lower
vernal sheaths and both surfaces of
cauline blades pubescent , often densely so;
spikelets (1.5-) 1.8-2.2 mm long; [of dry rocky or sandy
basic soil and
barrens ]
9 Often only lower
culm nodes bearded ;
internodes glabrous ; at least middle and upper
cauline blades glabrous ;
spikelets 1.4-2.8 mm long; [mostly of wet acid soils and
mesic to dry woodlands].
10 Spikelets (2.0-) 2.2-2.8 mm long; first
glume 0.5-1.3 mm long; fertile
lemma 1.8-2.3 mm long; lowest
vernal cauline blades pubescent at least abaxially
10 Spikelets 1.4-2.2 mm long; first
glume 0.3-0.9 mm long; fertile
lemma 1.4-1.7 mm long; lowest
vernal cauline blades glabrous .
11 Spikelets 1.7-2.2 mm long; first
glume 0.6-0.9 mm long; fertile
lemma 0.7-1.0 mm wide
11 Spikelets 1.4-1.9 mm long; first
glume 0.3-0.6 (-0.8) mm long; fertile
lemma 0.6-0.8 mm wide
13 Spikelets (1.5-) 1.7-2.7 mm long, if shorter than 1.8 mm then fertile
lemma and
palea densely
papillose ;
culms soon
sprawling .
14 Spikelets (1.5-) 1.7-2.3 mm long,
glabrous (rarely
pubescent ); first
glume 0.7-1.1 mm long; fertile
lemma and
palea densely
papillose at 20×
14 Spikelets 2.2-2.7 mm long,
pubescent ; first
glume 1.0-1.4 mm long; fertile
lemma and
palea smooth or with a few weak
papillae at 20×
13 Spikelets 1.2-1.7 mm long; fertile
lemma and
palea smooth;
culms erect.
15 Leaf
blades involute and often
falcate , 3-6 cm long, about 1.5 mm wide when flattened, 20-50× as long as wide; lower
internodes often
strigose ;
spikelets 1.2-1.4 mm long;
culms 5-20 cm long; [
endemic to c. and s. FL scrub]
15 Leaf
blades neither
involute (except apically) nor
falcate , 1-7 cm long, 1.5-7 mm wide, about 10× as long as wide; lower
internodes glabrous or sparsely
pilose , but not
strigose ;
spikelets 1.1-1.7 mm long;
culms 15-60 cm long; [wet sites, collectively widespread in coastal plain from NJ to TX and sparsely inland]
16 Leaf
blades (3-) 4-6 (-9) per
culm , pliable, 1-3.5 (-5) cm long, 1.5-4 mm wide, the
margins flat and sharp-
edged , gray-green to white-beige, 0.1 mm wide or less;
spikelets 1.2-1.5 mm long,
pubescent or
glabrous ;
culms to 40 cm long
16 Leaf
blades 3-4 per
culm , firm, 2-6 (-8) cm long, 2-6 (-8) mm wide, at least one
margin cartilaginously thickened, the edge usually rounded, white-beige to green-stramineous, 0.1-0.2 mm wide;
spikelets (1.1-) 1.3-1.7 mm long,
pubescent ;
culms to 60 cm long
17 Cauline leaves mostly basally disposed, strongly
ascending , much larger than the 2-3
remote middle and upper
cauline leaves of fertile
culms ;
spikelets 2.4-2.9 mm long;
culms branch from
basal and lower
nodes , but are not known to produce
autumnal inflorescences ; [Wet pine
savannas and seepages;
endemic to Gulf Coastal Plain]
17 Cauline leaves well-distributed along the
culm , > 3, gradually reduced upward and often spreading;
spikelets 0.9-2.6 mm long;
culms produce
autumnal inflorescences from lower, middle, and/or upper
nodes , if from lower only, then
spikelets only 0.9-1.2 mm long; [collectively widespread, habitats various].
18 Fertile
lemma and
palea densely
papillose ;
ligule usually
ciliate , rarely an eciliate membrane 0.1-0.3 mm long;
culms weak, soon
sprawling over
vegetation
18 Fertile
lemma and
palea smooth, with few or no
papillae ;
ligule always
ciliate .
19 Spikelets 0.9-1.5 mm long;
vernal blades 1-4 mm wide;
culms stiffer, erect to
ascending .
20 Spikelets 0.9-1.2 (-1.4) mm long;
blades 1.5-4 (-5) cm long, 1-2.5 (-3) mm wide, mostly 15-20 times as long as wide;
autumnal plants cushion-forming
20 Spikelets 1.2-1.5 mm long;
blades 1-12 (-20) cm long;
autumnal plants not cushion-forming.
21 Leaf
blades 1-3 (-5) cm long, 1.5-3 (-4) mm wide, about 10 times as long as wide;
autumnal plants sparsely
tufted
21 Leaf
blades 4-12 (-20) cm long (the longer at least 7 cm), 2-4 mm wide, 20-30 (-50) times as long as wide
19 Spikelets 1.4-2.6 mm long;
vernal blades 3-15 mm wide (if
spikelets < 1.6 mm long and
vernal blades < 5 mm wide, then larger
blades > 5 cm long in
D. caerulescens ).
22 Widest
vernal cauline blades 7-15 mm wide; upper
sheaths often
glutinous -
warty ;
spikelets 2.1-2.6 mm long, some or most
acute to beaked, second
glume and
sterile lemma extending 0.3-0.5 mm beyond fertile
lemma in at least some
spikelets
22 Widest
vernal cauline blades 3-10 mm wide; upper
sheaths not
glutinous -
warty ;
spikelets 1.4-2.3 mm long, blunt to subacute, second
glume and
sterile lemma often equal to or shorter than fertile
lemma , or extending < 0.3 mm beyond it.
23 Spikelets 1.4-1.8 mm long; first
glume 0.3-0.8 mm long; fertile
lemma 1.3-1.5 mm long; mature
vernal panicles usually short-
exserted with
ascending branches; fresh foliage bluish-
glaucous
23 Spikelets 1.7-2.3 mm long; first
glume 0.6-1.1 mm long; fertile
lemma 1.6-1.9 mm long; mature
vernal panicles exserted with spreading branches; fresh foliage not bluish-
glaucous .
24 Vernal panicle smooth to weakly
scabrous , the
scabrousness usually confined to the
pedicels ;
vernal cauline blades spreading to
deflexed ,
flexuous ;
autumnal form densely bushy-
fascicled , essentially forming one large mass of clustered leaves [of wet-
mesic to dry
woods and thickets]
24 Vernal panicle moderately to densely
scabrous , increasingly so from
rachis to branches to
pedicels ;
vernal cauline blades stiffly erect;
autumnal fascicles forming isolated clusters of leaves [of wet pine
savannas and open swamps]