This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
A low perennial succulent herb, with linear entire basal leaves and monoecious flowers, the staminate solitary or two together at the summits of slender scapes, the pistillate sessile among the leaves. Sepals 4 Corolla of the staminate flowers with a somewhat urceolate tube, and a spreading 4-lobed limb. Corolla of the pistillate flowers urn-shaped, 3-4-toothed. Staminate flowers with 4 long-exserted stamens, their filaments filiform, the anthers ovate. Pistillate flowers with a single ovary and a long-exserted filiform style. Fruit an indehiscent 1-seeded nutlet. [Latin, shore.]
Two known species, the following typical, the other in southern South America.
Plantago uniflora L. Sp. Pl. 115. 1753. Littorella lacustris L. Mant. 2: 295. 1771. Littorella uniflora Ascherson, Fl. Brand. 544. 1864.
Tufted, usually growing in mats; leaves bright green, 1'-3' long, 1/2'-1" wide, spreading or ascending, mostly longer than the scapes of the staminate flowers, which bear a small bract at about the middle; sepals lanceolate, mostly obtuse, with a dark green midrib and lighter margins, sometimes only 3 in the fertile flowers; stamens conspicuous, 4"-6" long; corolla-lobes ovate, subacute; pistillate flowers very small; nutlet about 1" long.
Borders of lakes and ponds, Maine and Vermont to Minnesota, Newfoundland, Nova Scotia and Ontario. July-Aug.