PONTEDERACE^:. 369 



feet high, forked. Flowers greenish-white, on filiform axillary pedicels which 

 are longer than in the preceding. Smooth Twisted Stalk. 



ORDER CXXXIV. PONTEDERACE^E. PONTEDERADS. 



Perianth tubular, colored, 6 -parted, more or less irregular ; 

 aestivation circinate. Stamens 3 6, unequal, perigynous. 

 Ovary free, more or less completely 3-celled ; style 1 ; stigma 

 3 6-cleft. Capsule 3-celled, 3-valved, loculicidal. Seeds nu- 

 merous, with somewhat mealy albumen. Aquatic or marsh 

 plants. Leaves sheathing at the base, with parallel veins. 



1. PONTEDERIA. Linn. Pickerel Weed. 

 (In honor of Julius Pontedera, professor of botany at Padua.) 

 Perianth tubular, 6-cleft, 2 -lipped ; under side of the tube 

 perforated with 3 longitudinal foramina; the lower part per- 

 sistent, calycine. Stamens 6, unequally inserted, 3 near the 

 base and 3 near the summit of the tube. Utricle muricate, 

 1-seeded. 



1. P. cm-data Linn. : leaves subradical, oblong-cordate ; flowers in 

 crowded spikes ; segments of the perianth oblong. 



Ponds. Can. to Car. W. to Ark. Aug. 7J.. Stem 1 2 feet long, bearing 

 a single leaf with the base of the petiole sheathing. Flowers aggregated by 

 twos and threes, sessile, bright-blue. Common Pickerel Weed. 



2. P. angustifolia Pursh. : leaves elongated-triangular, truncate and 

 subcordate at the base ; segments of the perianth linear-lanceolate. P. 

 cor -data ,var. angustifolia Torr. P. mucronata Raf. 



Beach pond, Westchester county, N. Y. Dr. S. B. Mead. Mountain lakes. 

 N. Y. to Car. Pursh. July. ^. Flowers blue, smaller than in the preceding 

 species, of which, however, it may be only a variety. 



Narrow-leaved Pickerel Weed. 



2. HETERANTHERA. R. <$ P. Heteranthera. 



(From the Greek erfpn? , different, and avvp, anther ; the anthers in the same 

 flower being dissimilar.) 



Flowers in a spathe. Perianth with a long and slender tube ; 

 border 6 -parted, equal. Stamens 3. Anthers of 2 forms. 

 Capsule 3-celled, many-seeded, opening at the angles ; dissepi- 

 ment contrary. 



H. reniformis R. <$ P. : leaves orbicular-reniform ; spathe oblong, acumi- 

 nate, 3 5-flowered. H. acuta Pursh. Leptanthus reniformis Mich. 



Overflowed bunks. N. Y. to Virg. July, Aug. %. Stem prostrate and 

 rooting in the mud, partly floating, 6 18 inches long. Leaves semicircularly 

 nerved, on petioles 2 3 inches long. Flowers white, 3 5 in a spathe. 



16* 



