Part 7 - UNC Herbarium

POACEAE 899
7 Panicles constricted, 0.3-1.6 cm wide; spikelets subsessile to short-pediceled; summit of fertile
palea not enclosed by fertile lemma ......................................................................P. hemitomon
7 Panicles > 1 cm wide; spikelets short to long-pediceled; summit of fertile palea enclosed by
fertile lemma; [subgenus Agrostoides, section Agrostoidea].
8 Plants tufted, without rhizomes; culms strongly compressed below; fertile lemma 1.3-1.5
mm long................................................................................P. rigidulum var. condensum
8 Plants rhizomatous; culms slightly compressed below; fertile lemma 1.8-2.2 mm long.
9 Rhizomes short, usually < 3 cm long; leaves 20-50 cm long, 4-18 mm wide;
spikelets 2.5-3.9 mm long, acuminate; first glume with 3-5 green nerves...................
.................................................................................................. P. anceps var. anceps
9 Rhizomes elongate, often > 4 cm long; leaves 10-30 (-40) cm long, 2-10 mm wide;
spikelets 2.2-2.8 mm long, acute to short-acuminate; first glume with 1-3 green
nerves................................................................................P. anceps var. rhizomatum
4 Panicle > 2 cm wide at maturity.
10 Plants from a cluster of fibrous roots, without rhizomes or hard knotty crowns, annual.
11 First glume 1/5 to 1/4 length of spikelet, broadly rounded to truncate; sheaths usually glabrous;
nodes glabrous; [subgenus Panicum, section Dichotomiflora]............................................................
..........................................................................................P. dichotomiflorum var. dichotomiflorum
11 First glume 1/3 to 1/2 length of spikelet, acute to subacute; sheaths villous or hispid; nodes often
bearded; [subgenus Panicum, section Panicum].
12 Spikelets 4.5-6 mm long; panicle branches often nodding or drooping at maturity.....................
................................................................................................................................P. miliaceum
12 Spikelets 1.8-3.6 mm long; panicle branches ascending-spreading at maturity.
13 Spikelets long-acuminate, (2.6-)3.0-3.6 mm long; mature panicle slender, usually 2-3
times as long as wide.............................................................................................P. flexile
13 Spikelets short-pointed to acuminate, 1.8-2.5 (-2.8) mm long; mature panicle usually > ½
as wide to wider than long.
14 Panicle usually equal to or longer than culm; largest blades usually 10-20 mm wide;
spikelets acuminate, lanceolate to lance-ovoid ..........................................P. capillare
14 Panicle usually not as long as culm; largest blades usually 10 mm or less wide;
spikelets short-pointed, ellipsoid, ovoid, or obovoid.
15 Herbage purple-tinged; blades 2-6 mm wide, ascending; pulvini glabrous to
sparsely pilose; spikelets 1.8-2.2 mm long, > 2× as long as wide; mature fertile
lemma blackish .............................................................................P. lithophilum
15 Herbage yellow-green to green; blades 2-12 mm wide, spreading; pulvini
glabrous or pilose; spikelets 1.4-2.4 mm long, < 2× as long as wide; mature
fertile lemma straminous.
16 Culm blades 5-12 mm wide; blade of flag (inflorescence bract) usually >
½ as long as panicle; panicle ellipsoid to obovoid; pulvini glabrous;
secondary panicle branches and pedicels divergent; spikelets 1.9-2.4 mm
long .......................................................................................... P. gattingeri
16 Culm blades 2-6 mm wide; blade of flag usually < ½ as long as panicle;
panicle broadly ovoid to deltoid; pulvini pilose; secondary panicle
branches and pedicels appressed; spikelets 1.4-2.1 mm long.......................
........................................................................................P. philadelphicum
10 Plants with rhizomes or hard knotty crowns, perennial.
17 Plants with rhizomes; fertile lemma 1.6-4 mm long.
18 First glume truncate apically ........................................................................................ P. repens
18 First glume acute to obtuse.
19 Culms slightly compressed below; ligules 0.5 mm long or less; spikelets subsessile and
subsecund, usually some obliquely bent above the first glume; fertile lemma 1.8-2.2 mm
long; [subgenus Agrostoides, section Agrostoidea].
20 Rhizomes short, usually < 3 cm long; leaves 20-50 cm long, 4-18 mm wide;
spikelets 2.5-3.9 mm long, acuminate; first glume with 3-5 green nerves...................
.................................................................................................. P. anceps var. anceps
20 Rhizomes elongate, often > 4 cm long; leaves 10-30 (-40) cm long, 2-10 mm wide;
spikelets 2.2-2.8 mm long, acute to short-acuminate; first glume with 1-3 green
nerves................................................................................P. anceps var. rhizomatum
19 Culms terete; ligules 1-6 mm long; spikelets pediceled and not at all secund, essentially
straight; fertile lemma 2-4 mm long; (subgenus Panicum, section Repentia].
21 Panicle narrow, the branches erect; sheaths longer than internodes; spikelets 4.3-7.7
mm long; fertile lemma 3-4 mm long.
22 Rhizomes usually elongate; culms solitary to loosely tufted, 0.2-1.5 m tall;
leaves 0.7-3.6 dm long; panicles 2-6 cm wide, the primary branches usually 1-2