1 Spathes absent;
inflorescence open and repeatedly branched; [tribe
Tradescantieae ]
1 Spathes present, single or paired;
inflorescence compact, unbranched.
2 Spathes paired, terminating the stem, resembling foliage leaves in size, shape, texture, and coloration; [tribe
Tradescantieae ]
2 Spathes single (or paired in
Callisia ), either terminal or
axillary , differing from the foliage leaves (in
Commelina folded, heart-shaped when spread, and usually pale-green, in
Cuthbertia and
Murdannia scale -like,
scarious , and inconspicuous, sometimes hidden by foliage leaves in
Murdannia ).
3 Spathe folded, heart-shaped when unfolded, usually pale-green, closely subtending and surrounding the flower
pedicels ;
petals unequal, the 2 upper
petals larger and usually more deeply colored than the lower
petal (which is sometimes absent); [tribe
Commelineae ]
4 Leaves not
glaucous ;
spathe folded; fertile
stamens 3, their
filaments glabrous ; [collectively widespread in our region]
4 Leaves
glaucous ;
spathe open; fertile
stamens 6 (though of 4 disparate forms), their
filaments bearded with purple or purple-and-yellow
hairs ; [TX only in our region]
3 Spathe scale -like,
scarious , and inconspicuous, not closely subtending and surrounding the flower
pedicels ;
petals equal, in both size and coloration.
5 Leaves
linear , > 20× as long as wide;
petals bright pink (rarely white); [tribe
Tradescantieae ]
5 Leaves
lanceolate , < 20× as long as wide;
petals white, pink, purplish, or bluish.
6 Fertile
stamens 0-6, all fertile (no
staminodes );
petals white to pink; [tribe
Tradescantieae ]
1 Leaves broad, < 4× as long as wide.
2 Floating leaves
peltate
2 Floating or
emersed leaves
cuneate to rounded at
base .
3 Floating leaves diamond-shaped, prominently
serrate
3 Floating or
emersed leaves
elliptic or suborbicular.
4 Leaves
emersed or floating, suborbicular or
elliptic (if
emersed , then suborbicular; flowers 3
-merous ; [
Monocots ].
5 Leaves
emersed , suborbicular
5 Leaves floating,
elliptic
1 Leaves narrow, > 4× as long as wide.
6 Leaves 0.3-1.4 cm long, very numerous and tightly spaced
6 Leaves 2-35 cm long, fewer and scattered along the stem.
7 Leaf divided into a
sheath and
blade , with a
ligule 0.5-8 mm long at the juncture;
inflorescence a
spike ,
raceme , or
panicle of
spikelets
7 Leaf not divided into a
sheath and
blade , but if basally
sheathing lacking a
ligule (though sometimes with 1-2 conspicuous
stipules );
inflorescence various, but not as above.
8 Leaves
terete , to 35 cm long, 0.3-2 mm wide; plants of marine habitats, growing
submersed in salt water; [FL and the Gulf Coast of AL, MS, and LA]
8 Leaves flat or
terete , to 200 cm long; plants of fresh or
brackish waters (if of marine waters,
Zostera , the leaves obviously flat, 1.5-6 mm wide); [collectively widespread].
9 Leaves
filiform ,
terete or nearly so;
stipules present,
adnate to the leaf
base and forming a
sheath around the stem > 10 mm long.
10 Stipule free at its tip, the
sheathing portion not appearing
inflated ; flowers > 2, in an
interrupted spike
10 Stipule adnate its
entire length to the leaf
base , appearing
inflated ; flowers usually 2, on a flexous, elongate
peduncle
9 Leaves flat;
stipules absent, or if present, either free or
adnate to the leaf
base and forming a
sheath for < 10 mm.
11 Leaves lacking a
midvein ;
perianth parts 6, yellow
11 Leaves with a
midvein ;
perianth parts 0 or 4, variously colored (not yellow).
12 Plants
pubescent (at least on the upper stem); leaves
pinnately veined; [
Eudicots ]
12 Plants nearly or entirely
glabrous ; leaves with parallel
venation ; [
Monocots ].
13 Inflorescence a
spike , terminal or
axillary ; with or without a
spathe ;
perianth lacking.
14 Inflorescence a
cylindrical ,
interrupted spike , lacking a
spathe ; leaves either parallel-margined or variously with a narrow
blade differentiated from a
petiole ; [fresh to
brackish waters]
14 Inflorescence either a flattened
spike sheathed by a
spathe -like
bract , or solitary; leaves parallel-margined, to 20 dm long; [
saline (marine) to
brackish waters].
15 Leaves with a notched or tricuspidate
apex ; flowers solitary; [e. NC southward]
15 Leaves with a rounded
apex ; flowers in a flattened
spike sheathed by a
spathe -like
bract ; [e. NC northward]