3 8o 



PONTEDERIACEAE. 



leaves mostly reniform, sometimes cordate -ovate. 

 Leaves ovate or oval, sometimes slightly cordate. 

 Leaves linear, grass-like, floating. 



1. H. reniformis. 



2. H. limosa. 



3. H. dubia. 



i. Heteranthera reniformis R. & P. Mud 

 Plantain. (Fig. 916.) 



Heteranthera reniformis R. & P. Fl. Per. i: 43. 1798. 

 Leptanthus reniformis Michx. Fl. Bor. Am. i: 25. 1803. 



Stems creeping in the mud, rooting at the nodes. Leaves 

 cordate or reniform, rarely cordate-ovate and acute, the 

 blades 6 // -i5 // long, 8 // -i6 // wide; petioles sheathing, \'-t\f 

 long; spathe 2-5-flo\vered; tube of the perianth straight or 

 slightly curved, slender, about 4" long, its lobes shorter; 

 flowers white or pale blue; anthers basifixed, the 2 upper 

 oval, the other on a longer filament and linear. 



In mud or shallow water, Connecticut to New Jersey, Illinois 

 and Kansas, south to Louisiana, and in South and Central 

 America. 



2. Heteranthera limosa (S\v.) Willd. 

 Smaller Mud Plantain. (Fig. 917.) 



Pontederia limosa Sw. Prodr. 57. 1788. 



Heteranthera limosa Willd. Neue Schrift. Ges. Nat. 

 Fr. Berlin, 3: 439. 1801. 



Leptanthus ovalis Michx. Fl. Bor. Am. i: 25. 1803. 



Stems commonly much branched from the base, 

 >'-\5 f long. Leaves numerous, oval or ovate, ob- 

 tuse at the apex, rounded or slightly cordate at the 

 base, i' long or less; petioles 2'-$' long; spathes 

 i-flowered, often on peduncles i' long or more; 

 flowers white or blue, usually larger than those of 

 the preceding species; filaments equal or nearly 

 so; anthers linear, often sagittate. 



In mud or shallow water, Virginia to Kentucky and 

 Missouri, south to Florida, Louisiana and throughout 

 tropical America. 



3. Heteranthera dubia (Jacq.) MacM. Water Star-grass. (Fig. 918.) 



Commelina dubia Jacq. Obs. Bot. 3: 9. pi. 59. 1768. 

 Leptanthus gramineus Michx. Fl. Bor. Am. i: 25. 1803. 

 Heteranthera graminea Vahl. Enum. 2: 45. 1806. 

 Schollera graminea A. Gray, Man. 511. 1848. 

 Heteranthera dubia MacM. Met. Minn. 138. 1892. 



Aquatic, stem slender, forked, often rooting at the 

 nodes, 2-3 long. Leaves linear, flat, elongated, acut- 

 ish, finely parallel-nerved, their sheaths thin, furnished 

 at the top with small acute stipule-like appendages; 

 flowers light yellow, the perianth-segments narrow; 

 stamens nearly equal; tube of the perianth i"-i}4" long; 

 spathe i-2-flowered; filaments dilated below; anthers 

 linear, i" long, sagittate; style shorter than the stamens; 

 stigma several-lobed; capsule i -celled with 3 parietal 

 placentae, many-seeded. 



In still water, Ontario to Oregon, south to Florida and 

 Mexico. Also in Cuba. Occasionally occurs in a small 

 form on muddy shores. July-Oct. 



