ORDER CXXXIII. — XYRroACE^. 543 



1. P. corda'ta, (L.) Stem none. Leaves cordate, obtuse, entire, mem- 

 branaceous, glabrous ; petioles very lonj,', sueculent. Floiccm in crowd- 

 ed spikes. 6'oro//a villous on the outer surface; the upper lip 3-parted. 

 the lower 3-cleft, with a yellow spot at the center; 3 of the st.-uncus at 

 the base of the tube, and 3 at the summit. — Blue. 2^. April— S«.pt. 

 Bogs and ditches. Wampee. 



2. P. lancifo'lia, (Muhl.) Stein none. Leaves oblong, hinceolate, 

 nearly linear whon young ; in other respects similar to the preceding 

 species. 



Genus II.— HETERANTHE'RA. Beau. 3—1. 

 (From Jieteros, variable, and antkera, an anther.) 



Flowers in a spathe, Perianth with the border G-parted, 

 equal. Stamens 3. Anthers unhke. Capsule 3-cellod, many- 

 seeded. 



1. H. renifor'mis, (R. &. P.) Stem partly floating. Leaves orbicular, 

 reniform, on petioles; spathe oblong, acuminate, 3 — 5-flowered. — White. 

 y. July — Aug. North Carolina. Mud Plantain. 



Genus III.— SYE'NA. Pursh. 3—1. {Mayaca, Sch.) 

 (In honor of Arnold Syen, of Leyden.) 



Sepals S, persistent. Petals 3. Stamens 3. St>jle 1. 

 Capsule 3-celled, 1-valved. 



1. S. fluviat'ilis, (Pursh.) /S^(???i herbaceous, partly submersed. Leaves 

 subulate, crowded. Flowers axillary, solitary, on peduncles longer than 

 the leaves. — Purple. If, June. In wet places. Middle Car. and Geo. 

 2 — 3 inches. Alijaca Michauxii, Schw. 



Order CXXXIIL— XYRIDA'CE^E. 



Sepals glumaceous, 3. Petals 3, unguiculate. Stamens 6, 

 with o fertile ones inserted into the claws of the petals, and 3 

 sterile ones alternate with the petals. Ovari/ single. Sti/le 3- 

 cleft. Capsule 1 -celled, 3-valved, many-seeded, with parietal 

 placentae. Herbaceous plants, with radical ensiform leaves. 

 Flowers in terminal imbricate heads. 



Genus I— XY'RIS. L. 3—1. 

 (From xuros, acute, from the shape of its leaves.) 



Sepals 3, glumaceous, somewhat cartilaginous. Petals 3, 

 equal, crenate. Stigma 3-cleft. 



1. X. FLEXUo'sA, (Ell.) Stem erect, spiral, dilated at the summit, 

 furrowed with two lines, glabrous. Leaves ensiform, spiral, phcathing. 

 Flowers in terminal imbricate heads. Bracts ovate, rigid, indo.Mng the 

 flower. Petals unguiculate. Capsule 1-celled, 3valved. Srrds numer- 

 ous, small.— Yellow, n. July— Sept. Pine-barrens. Common. l> H, 



X. Carol iniana, >> alL 



2. X. fimbria'ta, (Ell.) Stem erect, slightly scabrous dilated nt th« 



