Voi,. II.] BUCKBEAN FAMILY. 623 



2. Limnanthemum aquaticum (Walt.) Britton. Larger Floating Heart. 



(Fig. 2891.) 



A nonymos aqua f tea Walt. Fl. Car. 109. 1788. 

 Villarsia aquatica Gmel. Syst i: 447. 1791. 



Menyanthes trachysperma Michx. Fl. Bor. Am. 

 i: 126. 1803. 



Limnanthemum trachyspermum A. Gray, Man. 

 Ed. 5, 390. 1867. 



Limnanthemum aquaticum Britton, Trans. N. 

 Y. Acad. Sci. 9: 12. 1889. 



Similar to the preceding species but stouter 

 and larger. Floating leaves cordate-orbicular, 

 thick, entire or repand, 2 / -6 / long, spongy, 

 and with the petioles and stolons densely 

 covered with minute pits; primary leaves 

 spatulate; pedicels slender, i'-3' long; tubers 

 linear-oblong, thicker; corolla white, 6 // -io // 

 broad; style none; seeds rough; capsule longer 

 than the calyx. 



In ponds, southern New Jersey and Delaware 

 to Florida and Texas. Tubers apparently less 

 abundant than in L. lacunosum. May- Aug. 



3. Limnanthemum nymphaeoides (L.) Hoffm. & Link. Water Lily 

 Floating Heart. (Fig. 2892.) 



Menyanthes nymphaeoides L. Sp. PI. 145. 

 1753- 



Limnanthemum nymphaeoides Hoffm. &. 

 Link, Fl. Port, i: 344. 1809. 



Stems long, creeping or buried in the 

 mud, ascending to the surface of the water, 

 branched, the upper nodes bearing a 

 petioled leaf and a cluster of flowers, or the 

 upper internodes very short and their 

 leaves apparently opposite. Petioles stout, 

 mostly longer than the ovate-orbicular 

 firm blades, which are 2 / -4 / broad; pedi- 

 cels stout, becoming ^ / -6 / long, not ac- 

 companied by tufts of tubers; flowers bright 

 yellow, i' in diameter, or more; corolla 

 segments short-fringed. 



Naturalized in ponds, District of Columbia. 

 Native of Europe and Asia. May-July. 



