''Glyceria acutiflora'', the creeping mannagrass, is a perennial grass found in the north-eastern United States and in north-eastern Asia. Its specific epithet ''acutiflora'' means "acute-flowered". It has a diploid number of 40.

Description

''Glyceria acutiflora'' is a coarse grass with flattened, slender culms growing high from decumbent bases. Its leaf sheaths overlap each other, with the highest overlapping the base of the

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

. Its

ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many grasses (Poaceae) and sedges. A ligule is also a strap-shaped extension of the corolla, such as that of a ...

s are long. Its scabrous leaf blades are long and wide. Its simple or subsimple panicle is long, with appressed or somewhat spreading floral branches. Its subsessile spikelets are long with five to thirteen flowers. Its acute

glume In botany, a glume is a bract (leaf-like structure) below a spikelet in the inflorescence (flower cluster) of grasses (Poaceae) or the flowers of sedges (Cyperaceae). There are two other types of bracts in the spikelets of grasses: the lemma and ...

s are unequal, with lower glumes being and upper glumes long. Its seven-veined

lemma Lemma may refer to: Language and linguistics * Lemma (morphology), the canonical, dictionary or citation form of a word * Lemma (psycholinguistics), a mental abstraction of a word about to be uttered Science and mathematics * Lemma (botany), a ...

s are long, strongly acute, and scabrous; its bicuspidate paleas exceed its lemmas by . The grass flowers from May to July and rarely into August. The long paleas of ''G. acutiflora'' make it one of the most distinctive species of ''Glyceria'' in North America. When immature and still growing, the grass resembles ''

Glyceria borealis ''Glyceria borealis'' is a species of ''Glyceria'' known by the common names northern mannagrass, boreal mannagrass, and small floating mannagrass. It is native to much of the northern half of North America, where it has a widespread distribution ...

''.

Habitat and distribution

''Glyceria acutiflora'' can be found growing in muddy pools and the margins of ponds from New Hampshire to Michigan and south to Tennessee and Missouri. The grass is a problematic weed in China, germinating over a wide range of temperatures and being resistant to osmotic and salt stress.

References

{{Taxonbar, from=Q15516892 acutiflora Plants described in 1840