Glyceria canadensis
Glyceria striata
Canada mannagrass, Canadian mannagrass, rattlesnake manna grass, rattlesnake-grass
fowl manna grass, glycerie striee, ridged glyceria, ridged manna grass
60-150 cm tall, 2.5-5 mm thick, erect or the bases decumbent.
20-80 (100) cm tall, (1.5)2-3.5 mm thick, not or only slightly spongy, sometimes rooting at the lower nodes.
retrorsely scabridulous to scabrous, keeled;
ligules 2-6 mm;
blades 8-36 cm long, 3-8 mm wide, abaxial surfaces smooth or scabrous, adaxial surfaces scabridulous to scabrous.
smooth to scabridulous, keeled, sometimes weakly so;
ligules 1-4 mm, usually rounded, sometimes acute to mucronate, erose-lacerate;
blades 12-30 cm long, 2-6 mm wide, abaxial surfaces smooth or scabridulous, adaxial surfaces scabridulous to scabrous.
10-30 cm long, 10-20 cm wide, pyramidal, open, nodding;
branches 7-20 cm, lax, divergent, often drooping, with 15-60+ spikelets;
pedicels 2.5-9 mm.
6-25 cm long, 2.5-21 cm wide, pyramidal, open, nodding;
branches 5-13 cm, straight to lax, lower branches usually strongly divergent to drooping at maturity, sometimes ascending, with 15-50 spikelets, these often confined to the distal 2/3;
pedicels 0.5-7 mm.
3-8 mm long, (2.5)3-5 mm wide, laterally compressed, oval in side view, with 2-10 florets.
1.8-4 mm long, 1.2-2.9 mm wide, laterally compressed, oval in side view, with 3-7 florets.
narrowing from midlength or above to the broadly (> 45°) acute or rounded apices, 1-veined, veins terminating below the apices;
lower glumes 0.6-2.4 mm, ovate to rectangular;
upper glumes 1.5-2.5 mm, lanceolate;
rachilla internodes 0.2-0.5 mm;
lemmas 1.8-4 mm, ovate in dorsal view, 5-7-veined, veins evident but not raised distally, smooth over and between the veins, apices acute, prow-shaped;
paleas 0.1-0.8 mm shorter than lemmas, lengths 1.5-1.8 times widths, almost round in dorsal view, keels well developed, not winged, tips incurved, apices narrowly notched between the keels;
anthers 2, 0.4-0.5 mm, dehiscent at maturity.
ovate, 1-1.5 times longer than wide, narrowing from midlength or above, veins terminating below the apical margins, apices often splitting with age;
lower glumes 0.5-1.2 mm, rounded to obtuse;
upper glumes 0.6-1.2 mm, acute or rounded;
rachilla internodes 0.1-0.6 mm;
lemmas 1.2-2 mm, ovate in dorsal view, veins raised, scabridulous over and between the veins, apices acute, prow-shaped;
paleas slightly shorter than to equaling the lemmas, lengths 1.5-3 times widths, keeled, keels not winged, tips pointing towards each other, apices narrowly notched between the keels;
anthers 2, (0.2)0.4-0.6 mm, purple or yellow.
1.5-2 mm.
0.5-2 mm.
= 20 [reports of 28 are questionable].
Glyceria canadensis
Glyceria striata
Glyceria canadensis is an attractive native species that grows in swamps, bogs, lakeshore marshes, and wet woods throughout much of eastern North America, extending from eastern Saskatchewan to Newfoundland, Illinois, and northeastern Tennessee. It is now established in western North America, having been introduced as a weed in cranberry farms. It forms sterile hybrids with G. striata; the hybrids are called G. xottawensis Bowden. For further comments, see p. 77.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Glyceria striata grows in bogs, along lakes and streams, and in other wet places. Its range extends from Alaska to Newfoundland and south into Mexico. Plants from the eastern portion of the range have sometimes been treated as G. striata var. striata, and those from the west as G. striata var. stricta (Scribn.) Fernald. Eastern plants tend to have somewhat narrower leaves and thinner culms than western plants, but the variation appears continuous. In the west, larger specimens are easy to confuse with G. elata. The two species are sometimes found growing together without hybridizing; this and molecular data (Whipple et al. [in prep.]) support their recognition as separate species. The differences between the two in growth habit and stature are evident in the field; they are not always evident on herbarium specimens. In its overall aspect, G. striata also resembles G. pulchella, but it has somewhat more lax panicle branches in addition to smaller spikelets and florets.
Glyceria xgatineauensis Bowden is a sterile hybrid between G. striata and G. melicaria. It resembles G. melicaria but has longer (up to 12 cm), less appressed panicle branches and is a triploid with 2n = 30. It was described from a population near Eardley, Quebec. An additional specimen, tentatively identified as G. xgatineauensis, was collected in 1929 from French Creek in Upshur County, West Virginia.
Glyceria xottawensis Bowden is a sterile hybrid between G. striata and G. canadensis. It is intermediate between the two parents, and is known only from the original populations near Ottawa. It has sometimes been included in G. xlaxa (Scribn.) Scribn. [=G. canadensis var. laxa]; that taxon often produces viable seed, indicating that it is not a hybrid.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Lemmas 2.4-4 mm long; spikelets 5-8 mm long, with 4-10 florets; lower glumes 1.6-2.4 mm long; upper glumes acute | var. canadensis |
1. Lemmas 1.8-2.5 mm long; spikelets 3-5 mm long, with 2-5 florets; lower glumes 0.6-1.3 mm long; upper glumes usually rounded, sometimes acute | var. laxa |
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