Marsh herbs, with flowers having 3 distinct sepals and 3 distinct petals, pistils either apocarpous or separating at maturity into distinct carpels, and hypogynous stamens 6-many. Flowers on scapes or scape-like stems. Leaves sheathing at the base either rush-like or, when broad, mostly heart-shaped or arrow-shaped.
* Calyx and corolla both greenish. Carpels more or less united, but spreading at maturity. Leaves rush-like and fleshy, or grass-like.
1. Triglo'chin. Flowers small, in a spike or close raceme, without bracts. Carpels united to the top; when ripe, splitting away from a central persistent axis.
2. Scheuchzeria. A low hog-herb, with a creeping jointed rootstock, and grass-like leaves. Stamens 6. Carpels 3, globular, nearly distinct.
(These two genera are included in Naiadaceae in Macoun's Catalogue.)
** Calyx green, persistent. Corolla white. Pistil apocarpous. Leaves with distinct blades and petioles.
3. Alls'ma. Flowers perfect. Stamens usually 6. Carpels numerous, in a ring. Leaves all radical. Scapes with whorled panicled branches.
4. Sagittaria. Flowers monoecious, sometimes dioecious. Stamens numerous. Carpels numerous, in more or less globular heads. Leaves arrow-shaped, but varying greatly. Flowers mostly in whorls of 3 on the scapes, the sterile ones uppermost.
1. T. palus'tre, L. A slender rush-like plant, 6-18 inches high, found growing in bogs northward. Carpels 3, awl-pointed at the base, splitting away from below upwards. Spike or raceme slender, 3 or 4 inches long.
2. T. marit'imum, L. The whole plant is stouter than No. 1, and the carpels are usually 6 in number. - Atl. sea-coast, and saline marshes.
L. Scheuchzeria S. palustris, L. Stem zigzag. Flowers in a loose terminal raceme, with sheathing bracts. - Bogs.
A. Planta'go, L., var. America'num, Gray. Leaves long-petioled, mostly oblong-heart-shaped, but often narrower, 3-9-nerved or ribbed, and with cross veinlets between the ribs. Flowers small, white, in a large and loose compound panicle. - Low and marshy places, often growing in the water.
* Filaments narrow, as long as the anthers.
1. S. varia'bilis, Engelm. Very variable in size and in the shape of the leaves. Scape angled. - Common everywhere in shallow water.
Var. obtusa, Engelm., is dioecious, and has large obtuse leaves.
Var. latifolia, Engelm., is monoecious, with large broad acute leaves.
Var. angustifolia, Engelm., has narrow leaves, with long and linear diverging lobes.
* * Filaments very short, with enlarged mostly glandular base.
2. S. heterophyl'la, Pursh. Scape weak and at length procumbent. Leaves lanceolate or lance-ovate, entire, or with one or two narrow basal sagittate appendages.
3. S. gramin'ea, Michx. Scape very slender, erect. Leaves varying from ovate-lanceolate to linear, scarcely ever sagittate.
4. S. calyci'na, Engelm., var. spongiosa, Engelm. Scape weak, and at length usually procumbent. Fertile flowers perfect. Leaves broadly halberd-shaped with wide-spreading lobes. Submerged leaves without blades. - Atl. Prov.