Glyceria nubigena
Glyceria maxima
great Smoky Mountain glyceria, great Smoky Mountain mannagrass
English watergrass, giant mannagrass, glycerie aquatique, reed manna grass, rough mannagrass, tall glyceria, tall mannagrass
100-200 cm tall, 3-5 mm thick, smooth.
60-250 cm tall, 6-12 mm thick, erect.
smooth or scabridulous, weakly keeled;
ligules 1-1.5 mm, truncate;
blades to 45 cm long, 6-10 mm wide, abaxial surfaces smooth or scabrous, adaxial surfaces scabrous.
scabridulous, keeled;
ligules 1.2-6 mm, rounded or with a central point, ligules of the lower leaves thick, stiff, and opaque, ligules of the upper leaves thinner and translucent;
blades 30-60 cm long, 6-20 mm wide, both surfaces smooth or adaxial surfaces scabridulous.
20-30 cm long, 7.5-14 cm wide, open, pyramidal;
branches 7.5-14 cm, spreading or reflexed, lax, with 16-80 spikelets;
pedicels 2-7 mm.
15-45 cm long, to 30 cm wide, open;
branches 8-20 cm, lax, strongly divergent or drooping at maturity, scabridulous, primary branches with 50+ spikelets;
pedicels 0.8-10 mm.
3.5-5.5 mm long, 2-3(3.5) mm wide, laterally compressed, oval in side view, with 3-5 florets.
5-12 mm long, 2-3.5 mm wide, somewhat laterally compressed, oval in side view, with 4-10 florets.
tapering from below midlength to the narrowly (< 45°) acute apices, veins not extending to the apices;
lower glumes 0.8-1.5 mm;
upper glumes 1.8-2.2 mm;
rachilla internodes about 0.5 mm;
lemmas 2.2-2.7 mm, 0.9-1.1 mm wide in dorsal view, veins distinctly raised, usually smooth over and between the veins, sometimes scabridulous over the veins, apices acute, prow-shaped;
paleas slightly shorter than the lemmas, lengths 2-2.7 times widths, keels not winged, tips incurved, apices narrowly notched between the keels;
anthers 2, about 1.5 mm, dehiscent at maturity.
unequal, usually the midvein of 1 or both reaching to the apices;
lower glumes 2-3 mm;
upper glumes 3-4 mm, longer than wide;
rachilla internodes 0.5-1 mm;
lemmas 3-4 mm, 7-veined, veins scabridulous, apices broadly acute to rounded, slightly prow-shaped;
paleas subequal to the lemmas, lengths more than 3 times widths, keels not winged, ciliate, tips not strongly incurved, curved to broadly notched between the keels;
anthers 3, (1)1.2-2 mm.
about 1.5 mm.
1.5-2 mm.
= 40.
= 60.
Glyceria nubigena
Glyceria maxima
Glyceria nubigena is known only from moist areas of balds and high ridges in the Great Smoky Mountains of North Carolina and Tennessee.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Glyceria maxima is native to Eurasia. It grows in wet areas, including shallow water, at scattered locations in the flora region. It is an excellent fodder grass, and may have been planted deliberately at one time (Dore and McNeill 1980). At some sites, the species appears to be spreading, largely vegetatively. It is easily confused with large specimens of G. grandis, but differs in its firmer, more prow-tipped lemmas as well as its larger lemmas and usually larger anthers.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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