1 Culm nodes, at least the lower, bearded (often retrorsely).

  2 Nodes with a viscid band below the beard; internodes and sheaths velvety-pubescent; vernal culm blades 9-20 cm long, 9-20 mm wide

  2 Nodes without a viscid band below the beard; internodes and sheaths glabrous, the lower sometimes sparsely hairy; vernal culm blades 3.5-14 cm long, 7-15 mm wide

1 Culm nodes glabrous or pubescent, but not bearded.

    3 Second glume and sterile lemma acute to short-acuminate, some in a given specimen 0.3 mm or more longer than fertile lemma.

      4 Ligule an eciliate membrane; peduncle scabrous; first glume 0.3-0.6 (-0.8) mm long, reniform to suborbicular

      4 Ligule a ciliate membrane or entirely ciliate; peduncle smooth; first glume 0.7-1.6 mm long, broadly ovate to lanceolate.

        5 Ligule a ciliate membrane; larger leaves 10-20 cm long; spikelets pubescent, (2.6-) 2.8-3.4 (-3.6) mm long; first glume (0.9-) 1.0-1.6 mm long

    3 Second glume and sterile lemma blunt to subacute, shorter than, equaling, or barely exceeding fertile lemma, never by as much as 0.3 mm.

          6 Ligule ciliate, 0.2-1.1 (-2.1) mm long; leaf blades 5-14 cm by 5-17 mm; second glume 0-0.3 mm shorter than fertile lemma.

             7 Culms 30-75 cm long; lower sheaths glabrous to sparsely papillose-pilose; panicle pulvini glabrous to sparsely pilose; spikelets 1.8-2.6 mm long; first glume narrowly triangular (triangular-ovate); second glume 0-0.1 mm shorter than fertile lemma

             7 Culms 60-150 cm long; lower sheaths papillose-pilose; panicle pulvini pubescent; spikelets 2.2-2.8 (-3.0) mm long; first glume broadly ovate; second glume 0.05-0.3 mm shorter than fertile lemma

          6 Ligule a ciliate or eciliate membrane (0-) 0.3-0.9 mm long; leaf blades 5-28 cm by 5-40 mm; second glume 0-0.1 mm shorter than fertile lemma.

               8 Lower sheaths papillose-hispid with spreading hairs; ligule a membrane 0.4-0.9 mm long; leaf blades 10-28 cm long

               8 Lower sheaths glabrous, puberulent, or softly villous basally; ligule either a membrane 0-0.3 mm long or a ciliate membrane 0.4-0.7 mm long; leaf blades 5-18 cm long.

                 9 Ligule a ciliate membrane 0.4-0.7 mm long; leaves 15-40 mm wide; spikelets 1.6-2.0 mm wide

                 9 Ligule a membrane 0-0.3 mm long; leaves 5-25 mm wide; spikelets 1.1-1.3 mm wide

                   10 Cauline blades 5-18 cm long, 6-14 mm wide, averaging about 10 × as long as wide, the margins nearly parallel; spikelets 2.9-3.7 mm long; first glumes 1.1-2.6 mm long, 2/5 or more as long as the spikelets

                   10 Cauline blades 7-12 cm long, (6-) 12-25 mm wide, ovate-lanceolate, averaging about 6 × as long as wide, the margins curved most of their length; spikelets 2.0-3.2 mm long; first glumes 0.5-1.0 mm long, about 1/4 as long as spikelets.

                     11 Culms erect; blades more nearly symmetrical; spikelets 2.0-3.2 mm long; sterile lemma apex usually blunt to rounded

                     11 Culms basally decumbent; blades strongly asymmetrical-falcate; spikelets 3.0-3.2 mm long; sterile lemma apex usually pointed

1 Lower cauline nodes bearded, the hairs usually retrorse.

  2 Spikelets glabrous.

    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

        5 Spikelets 1.2-1.4 mm long; sheaths spreading-pilose; vernal cauline blades 2-5 mm wide; ligule 1-2 mm long; node beard hairs usually spreading or reflexed; internodes glabrous

      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

  2 Spikelets pubescent.

             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

1 Lower cauline nodes glabrous or puberulent, but not bearded.

                       12 Spikelets pubescent.

                          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

                       12 Spikelets glabrous.

                                  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 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]