This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
(See illustration on p. 211.)
In common with other maritime plants our only knowledge of this grass is obtained from its present-day distribution in the N. Temperate Zone in Europe, N. Africa, Siberia, and N. America. It is found around the whole of the British coasts, except in Pembroke, Cardigan, Merioneth, Denbigh, Lines, as far north as the Shetlands. It is also a native of Ireland and the Channel Islands.
The seaside form of Manna Grass is a very universally dispersed maritime species, which is typically a salt-lover, and is found almost exclusively on coasts that are muddy or sandy, occurring in the same stations as G. distans and various other grasses.
The stem is round and smooth, the root fibrous, creeping, and with long trailing shoots, rooting and leafy. The leaves are acute, with a strong ridge, the margin rolled inwards, with smooth sheaths, and a long blunt lig;ule.
The flowers are borne on a one-sided panicle, which is branched and narrowed, with solitary or the lower 2-3 short branches, horizontal, sometimes turned down, with a nearly round rachis. The spikelets are 5-flowered and blunt, linear, 5-nerved, the empty glumes subacute. The lower palea is blunt apiculate, rolled inwards.
The plant is about 1 ft. high. It flowers in July. Seaside Manna Grass is perennial, increasing by means of its stolons.
The flowers are pollinated by the wind, and the stigmas mature first, ensuring cross-pollination. The stamens are 3, the styles are short or wanting, and the stigmas feathery, the spikelets being 5, in a narrowed panicle.
The fruit, covered by the glume, is light, and wind-borne.
This Manna Grass is a salt-lover, and grows in a saline soil. It is also a sand plant, and addicted to a sand soil or a dirty loam. A moth, Epichnopteryx reticella, is found to infest it.
Glyceria, R. Brown, is from the Greek glukeros, sweet, in allusion to the sweet grains, and the second Latin name refers to the habitat (maritime).
Essential Specific Characters: 339. Glyceria maritima, Mert. et Koch. - Root creeping, fibrous, leaves involute, ribbed, ligule blunt, panicle contracted, lower palea blunt, spikelets compressed.