ORDER 150. PONTEDERIACE^E. 721 



to 12, hypogynous, longer than the sepals; anthers introrsc; styles 3 ; 

 capsule 3-partible, co-seeded. 2 Herb glabrous, with a slender, rush- 

 like stem, dry, rush-like Ivs., and a raceme of 6 to 9 yellow fls. 

 P. tenuifolia Rich. Bogs, N. Car, (Curtis), S. Car. (Michx.) St. 1 to 2f liigh, 



from red, fibrous roots. Lvs. perennial*green, very narrow, sheathing at base, 



nearly If long. Caps, brown. 



ORDER CL. PONTEDERIACE^L PONTEDERIADS. 



Plants aquatic, with the leaves parallel-veined, mostly dilated at base. Fls. spatL- 

 aceous. Perianth tubular, colored, 6'parted, often irregular and circinate after 

 flowering. Stamens 3 or 6, unequal, perigynous. Ovary free, 3-celled. Style 1 . 

 Stigma simple. Capsule 3 (sometimes l)-celled, 3-valved, with loculicidal dehis- 

 cence. Seeds numerous (sometimes solitary), attached to a central axis. Albumen 

 farinaceous. 



Genera 6, species 30, found exclusively in America, E. Indies, and tropical Africa. They are 

 of no known use. 



GENEftA. 



Flowers irregular, blue. Stamens C. Utricle 1 -seeded ..,,.-... POVTF.DEKIA. t 



.Flowers regular. Anthers 8, of 2 forms. Leaves reniform HKTERANTUERA. 1 



Anthers 8, of one form. Leaves linear SCUVLI.KRA. 3 



1. PONTEDE V RIA, L. PICKEREL WEED. (In honor of Julius Pon* 

 tcdera, a botanic author and professor, of Padua, about 1720.) Perianth 

 bilabiate, tubular at base, under side of tlie tube split with 3 longitudi* 

 7ial clefts (the 2 lower sepals free), circinate after flowering and persis* 

 tent ; stamens unequally inserted, 3 near the base and 3 at the summit 

 of the tube; utricle 1-seeded (2 cells abortive). Lvs. radical, long* 

 petioled. St. 1-leaved, bearing a spike of blue fls, 



1 P. cordata L. Lvs. cordate-oblong, vbtuse ; petiole shorter than the peduncle ; 

 spike cylindrical, pubescent. If Can. and U. S. A fine, conspicuous plant, na 

 tive of the borders of muddy lakes, &c., growing in patches extending from the 

 shores to deep water. Stem thick, round, erect, arising 1 2f above the water, 

 bearing a single leaf. Leaves 4 7' by li 3'. very smooth and glossy, almost 

 sagittate, with veins beautifully arranged to conform to the margin. Flowers in 

 a spike, arising above the spathe, very irregular. Perianth 2-lipped, each lip 8- 

 cleft, always blue, appearing in July. 



/3. AXGUSTIFOLIA Torr. Lvs. narrow, truncate and subcordatc at base. 



2 P. lancifolia Muhl. Lvs. lance^obtong vr lance-linear, rather acute at each endj 

 petiole shorter than the peduncle; spike cylindrical, pubescent. Pools and 

 ditches, Ga, (Feay) and S. Car. More slender every way than the other, 15 to 30' 

 high. We can detect no difierence in its flowers, but the permanent difference 

 of the leaves is worthy of consideration, Apr., May. 



2. HETERAN'THERA, Ruiz & Pav. (Gr. t-rt'pa, otherwise, avQripd\ 

 the anthers being dissimilar in the same flower.) Spathe several- 

 flowered; tube of the perianth long and slender, limb 6-parted, equal ; 

 stamens 3 ; anthers of 2 forms, the lower oblong-sagittate, on a longer 

 filament ; capsule 3-celled, many-seeded. Lvs. mostly reniform, long- 

 petioled. 



H. renifortois R. & P. St> prostrate or floating ; Ivs. suborbicular, reniform of 

 auriculate at base ; spathe acuminate, few-flowered. On muddy or inundated 

 banks, Mid. and "W\ States. Stem 4' to a foot or more in length. Leaves $' by 

 if', on petioles 1- 2' long, with a broad sinus at base, find a >short, abrupt acumi- 

 nation. Spathe closely enveloping the 2 or 3 very evanescent, white flowers. 

 Tube of the perianth V long, limb in G oblong segments. Filament? inserted at 

 46 



