Part 7 - UNC Herbarium

POACEAE 911
4 Plants not dioecious, the florets perfect; lemmas and glumes not notably scarious and silvery; [collectively common
and widespread in our area]; [subgenus Poa].
5 Lemmas not webbed at the base.
6 Annual; culms decumbent to ascending and 1-3 dm long; inflorescence 2-8 cm long, the ascending branches
bearing crowded spikelets above the middle; lemmas 2.4-3.4 mm long; [section Ochlopoa].............. P. annua
6 Perennial; culms erect, 3-6 dm long; inflorescence 6-15 cm long, the widely spreading branches bearing a
few spikelets near the end; lemmas 3.2-4.4 mm long; [section Sylvestres] ...................................P. autumnalis
5 Lemmas webbed at the base.
7 Spikelets (most or all) modified into purplish bulblets; culm bulbous-thickened at ground level; [section
Bolbophorum] .................................................................................................................................... P. bulbosa
7 Spikelets normal; culm not bulbous-thickened.
8 Annual; [section Homalopoa] ...........................................................................................P. chapmaniana
8 Perennial.
9 Marginal veins of the lemma glabrous.
10 Nodes of the panicle mostly with 4-8 branches; lemmas pubescent or scabrous on the keel.
11 Sheaths glabrous; ligule 0.7-2.2 (-3.0) mm long; [section Sylvestres]................. P. alsodes
11 Sheaths scabrous; ligule (2.5-) 3-7 mm long; [section Pandemos] ......................P. trivialis
10 Nodes of the panicles mostly with 2 branches; lemmas glabrous on the keel; [section
Sylvestres].
12 Anthers 0.6-0.9 (-1.0) mm long; lemmas broad-acute, obtuse or truncate at the apex, the
keel and lateral margins of the lemma forming an apical angle of 42-82 degrees, firm at
the tip, the scarious tip absent or up to 0.25 mm long....................................... P. languida
12 Anthers 0.9-1.5 mm long; lemmas acute to acuminate at the apex, the keel and lateral
margins of the lemma forming an apical angle of 10-47 degrees, pliable at the tip, the
scarious tip prominent and 0.25-0.5 mm long..................................................P. saltuensis
9 Marginal veins of the lemma pubescent, at least basally.
13 Lower nodes of the panicles mostly with (1-) 2-3 branches.
14 Ligule truncate, 0-1 mm long; first glume 1.7-2.2 mm long, second glume 2.0-2.8 mm
long; anthers 0.5-0.7 mm long.......................................................................P. paludigena
14 Ligule rounded-ovate, 1-2 mm long; first glume 2.5-3.5 mm long, second glume 3.0-3.8
mm long; anthers 1.1-1.4 mm long.........................................................................P. wolfii
13 Lower nodes of the panicles mostly with (4-) 5 or more branches.
15 Lemmas 5-veined (intermediate veins well-developed); ligule ca. 1 mm long; [section
Sylvestres]......................................................................................................... P. sylvestris
15 Lemmas 3-veined (intermediate veins obscure); ligule either (2-) 3-5 mm long or 0.2-1 (-
1.5) mm long.
16 Ligule 0.2-1 (-1.5) mm long, truncate; culms 4-8 dm tall; anthers 1.2-1.6 mm long;
[section Stenopoa] ...................................................................................P. nemoralis
16 Ligule (2-) 3-5 mm long, ovate-triangular; culms 5-15 dm tall; anthers 0.8-1.2 mm
long; [section Pandemos]...........................................................................P. palustris
Poa alsodes A. Gray, Woodland Bluegrass. Mt (NC, VA), Pd (NC): rich forests; uncommon. May-June. Nova Scotia west
to SD, south to NC and IL; also in w. United States. [= RAB, C, F, G, HC, K, W, Z]
* Poa annua Linnaeus, Speargrass, Six-weeks Grass, Annual Bluegrass. Cp, Pd, Mt (GA, NC, SC, VA): fields, roadsides,
disturbed areas; common, introduced from Eurasia. April-May. [= RAB, C, F, G, GW, HC, K, W, Z]
* Poa arachnifera Torrey, Texas Bluegrass. Pd (GA, NC, SC): disturbed areas; rare, introduced from South America and w.
United States. April. [= RAB, HC, K]
Poa autumnalis Muhlenberg ex Elliott. Cp, Pd, Mt (GA, NC, SC, VA): moist or dry nutrient-rich forests; common. April-
May. NJ west to MI, south to FL and TX. [= RAB, C, F, G, GW, HC, K, W, Z]
* Poa bulbosa Linnaeus, Bulbous Bluegrass. Cp (NC, VA), Pd (GA, NC, VA): lawns; rare, introduced from Europe. April-
May. [= RAB, C, F, G, HC, K, Z]
Poa chapmaniana Scribner. Pd, Cp (GA, NC, SC, VA): low fields, roadsides, disturbed areas; common (VA Watch List).
April-May. DE west to IA, south to FL and LA. [= RAB, C, F, G, HC, K, W, Z]
* Poa compressa Linnaeus, Canada Bluegrass. Mt, Pd (GA, NC, SC, VA), Cp (NC, SC, VA): fields, roadsides, disturbed
areas; common, introduced from Europe. May-August. [= RAB, C, F, G, HC, K, W, Z]
Poa cuspidata Nuttall. Mt, Pd (GA, NC, SC, VA), Cp (GA, NC, VA): moist forests; common. March-April. NJ west to s.
IN, south to sw. GA. [= RAB, C, F, G, HC, K, W, Z]
Poa languida Hitchcock, Drooping Bluegrass. Mt (VA): ultramafic outcrop woodlands, barrens, and glades; rare (VA Rare
as P. saltuensis). April-May. VT and MA west to MN, south to PA, w. VA, KY, and IA. See comments under P. saltuensis. [=
C, F, G, HC, W; < P. saltuensis – K; = P. saltuensis Fernald & Wiegand ssp. languida (Hitchcock) A. Haines – Y]
* Poa nemoralis Linnaeus, Wood Bluegrass. Mt (NC, VA), Pd (VA): sandy creek bottoms; rare, introduced from Europe
(NC Watch List). [= C, F, G, HC; ? P. nemoralis ssp. nemoralis – K]
Poa paludigena Fernald & Wiegand, Bog Bluegrass. Mt (NC, VA): mountain bogs, especially in deep shade under shrubs;
rare (US Species of Concern, NC Endangered, VA Rare). April-May. NY west to MN, south to PA, w. NC, and IL. This