PONTEDERACE.E. 369 



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

 are longer than in the preceding. Smooth Twisted Stalk. 



Order CXXXIY. PONTEDERACE^.— 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. cordata Linn.: leaves subradical, oblong-cordate; flowers in 

 crowded spikes ; segments of the perianth oblong. 



Ponds. Can. to Car. W. to Ark. Aug. Ij.. — 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. arigustifolia Pursh. : leaves elongated-triangular, truncate and 

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

 cordata ^-vax. 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 Irspoi^ different, and avrjp, 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. cf« P. ; leaves orbicular-reniform ; spathe oblong, acumi- 

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



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

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

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



Mttd Plantain. 

 16* 



