ALISMACE^E. (WATEU-I'LANTAIN FAMILY.) 491 



shaped. Leaves or some of them commonly furnished with a blade. 

 (Flowers perfect, monoecious, or sometimes dioecious.) 



3. Alisma. Flowers perfect, with definite, mostly 6 stamens. Carpels flattened, whorled. 



4. Kihiiiodoiiis. Flowers perfect, with 6 - many stamens. Carpels capitate, ribbed. 



5. Sa- il I ai ia. Flowers monoecious, rarely diuecious, with indefinite, rarely few stamens. 



Carpels capitate, flattened, winged. 



1. TRIGLOCHIN, L. Arrow-grass. 



Sepals ami petals nearly alike (greenish), ovate, concave, deciduous. Sta- 

 mens 6 : anthers oval, on \cry short filaments. Pistils united into a 3-6-celled 

 compound ovary : stigmas sessile : ovules solitary. Pod splitting when ripe 

 into 3-0 carpels, which separate from a persistent central axis. — Perennials, 

 with rush-like, fleshy leaves, below sheathing the base of the wanddike naked 

 and jointless scape. Flowers small, in a spiked raceme, bractless. (Name 

 composed of rpels, three, ami -yXco^iV, point, from the three points of the ripe 

 fruit in No. 1 when dehiscent.) 



1. T. palustre, L. Scape (6'-18' high) and leaves slender ; fruit linear- 

 club-skaped ; the 3 carpels when ripe separating from below upwards leaving a 

 triangular axis, awl-pointed at the base. — Marshes, both fresh and brackish, New 

 York to Illinois, and northward. Aug. (Eu. ) 



2. T. maritimum, L. Scape (12' -20' high) and leaves thickish, fleshy, 

 fruit ovate or oblong, acutish, of 6 or rarely 5 carpels which are rounded at the base 

 and slightly grooved on the back ; the edges acute. — Salt marshes along the coast, 

 also salt springs in the interior, shore of the Great Lakes, and northward. — 

 Yar. elXtum (T. elatum, Nuit.) grows in cold and fresh bogs, from YV. New 

 York to Wisconsin, often 2^° high, and has the angles of the carpels sharper, 

 or almost winged. (Eu.) 



2. SCHEUCHZERIA, L. Scheuchzeria. 



Sepals and petals oblong, spreading, nearly alike (greenish-yellow), hut the 

 latter narrower, persistent. Stamens 6 : anthers linear. Ovaries 3, globular, 

 slightly united at the base, 2-3-ovuled, bearing flat sessile stigmas, in fruit 

 forming 3 diverging and inflated 1 -2-seeded pods, opening along the inside. — 

 A low bog-herb, with a creeping jointed rootstock, tapering into the ascending- 

 simple stem, which is zigzag, partly sheathed by the bases of the grass-like con- 

 duplicate leaves, and terminated by a loose raceme of a few flowers, with sheath- 

 ing bracts. (Named for John and John Jacob Scheuchzer, distinguished Swiss 

 botanists early in the 18th century.) 



1. S. pallistris, L. — Peat-hogs, New England to Pennsylvania, Illinois, <Y(AmuA l> 

 and northward. July. (Eu.) 



3. ALISMA, L. Water-Plantain. 



Flowers perfect. Petals involute in the hud. Stamens definite, mostly 6. 

 Ovaries many in a simple circle on a flattened receptacle, forming flattened cori- 

 aceous achenia, which are dilated and 2-3-keeled on the back. — Roots fibrous. 



