474 ALISMACE.E. (WATER-PLANTAIN FAMILY.) 



sterile flowers twice as long as those of the fertile ones ; acheuia obovate 

 beaked ; filaments smooth. (S. sagittifolia, hastata, pubescens, etc. of untlium.) 



Marshes, ditches, etc. July -Sept.- Scape l- 3 high, angled. Leaves 

 2' -12' long. 



* * Filaments short, thickened at the base. 



3. S. heterophylla, Pursh. Scape weak ; leaves linear or lanceolate, 

 and acute at each end, or elliptical, and obtuse or sagittate at the ba.se ; bracts 

 obtuse; sterile flowers on long and slender pedicels ; the fertile ones nearly 

 sessile; acheuia narrowly obovate, long-beaked. Schurlock's Spring, West 

 Florida, Tennessee, rare. Leaves 2' -4' long. Scape few-flowered, the low- 

 est whorl only bearing fertile flowers. 



4. S. graminea, Michx. Scape slender, commonly prostrate in fruit, 

 simple or branched; leaves linear or lanceolate, acute at each end, 3-nerved, 

 erect, the earliest mostly destitute of a blade; bracts membranaceous ; flowers 

 small, all on long filiform pedicels ; stamens 10-12, hairy at the base ; achenia 

 obovate, wing-keeled, beakless. Shallow ponds in the pine barrens. May- 

 Oct. Scape 10'- 15' high, usually longer than the leaves. 



5. S. filiformis, J. G. Smith. Leaves filiform, bladeless ; scape filiform, 

 much branched, 2 -3 long; whorls 6-10, remote; fertile flowers 1-2; 

 stamens 7 ; mature achenia not seen. Aquatic, floating in still water, Florida 

 and Alabama (J. G. Smith). 



6. S. macrocarpa, J. G. Smith. Leaves linear-lanceolate ; scape simple, 

 10'- 12' high ; whorls 3- 5 ; bracts ovate, connate ; fertile flowers 1 -3 ; sta- 

 mens about 12; achenia oblong-obovate, broadly winged, short-beaked, the 

 sides even. Margins of ponds, South Carolina (Curtis). 



7. S. teres, Watson. Leaves terete, mostly bladeless ; scape simple, 6'- 

 1 5' high, few-flowered ; bracts ovate, obtuse ; fertile flowers 1 - 2 ; stamens 1 2 ; 

 achenia round-obovate, short-beaked, crenately crested on the back and sides, 



Shallow water. South Carolina (Smith), aud northward. 



8. S. natans, Michx. Small ; leaves floating, ovate-oblong or elliptical, 

 obtuse at each end or the lowest slightly cordate, 5- 7-nerved, about as long 

 as the few-flowered scape ; bracts membranaceous, acute ; pedicels of the fer- 

 tile flowers stouter than those of the sterile ones, recurved in fruit ; stamens 

 7 or 8 ; achenia obovate, 3-ribbed on the back, short-beaked. Shallow ponds 

 and streams, Florida to South Carolina. June -Sept. Scapes 3' -6' long. 

 Leaves l'-2' long. 



Var. lorata, Chapm. Leaves strap-shaped, obtuse, without a blade, nerve- 

 less; scapes floating or erect ; flowers sometimes dioecious ; achenia conspicu- 

 ously beaked, pimpled. Brackish water, along the coast. May -Sept. 

 When growing in deep water the floating scapes are 2 - 3 long ; when on 

 muddy banks, only 3'- 5' high. 



Var. pusilla. Still smaller (l'-3' high) ; leaves linear or subulate, 

 mostly with a short blade, longer than the 2-9-flowered scape. With the 

 preceding. 



