544 PONTEDERIACE^E. (PICKEIIEL-WEED FAMILY.) 



large (£"-§" long), with short white membranaceous appendages. — From S. 

 New England southward, especially in New Jersey. — Often confouuded with 

 forms of No. 21, from which it is readily distinguished by the large, delicately 

 ribbed and not reticulated, appendaged seeds, and by the proportion of the inner 

 and outer sepals. 



Var. brachycephalus. Stem slender (1^°- 2^° high), bearing numer- 

 ous small and 3-5-fio\vered heads in a large and spreading panicle; flowers 

 greenish or light brown (li"-l£" long) ; sepals mostly obtuse, shorter than 

 the brown abruptly short-pointed pod ; style longer than in other forms ; seeds 

 smaller (}"-£" long), slender, with rather short appendages. — From Penn- 

 sylvania northwestward to Illinois and Wisconsin. — Sometimes confounded 

 with No. 18, and with small-flowered forms of No. 21. 



Var. COarctatUS. Stem slender, shorter (9' - 18' high), bearing fewer deep- 

 brown 3 - 5-flowered heads in a somewhat erect contracted panicle ; flowers as 

 large as in the last; sepals acute, or rarely obtusisb, much shorter than the 

 prismatic abruptly pointed deep-brown pod ; seeds as in the last, (J. acuminatus, 

 Ed. 2, and of most American authors, but not of Michaux). — New England 

 to Wisconsin and northward, southward to the mountains of Pennsylvania. 



-t— -t- Stamens 6. 



26. J. asper, Engelm. Stems tufted, erect (2° -3° high), terete, stout, 

 rigid, and with the rigid leaves rough ; panicle with rigid slightly spreading 

 branches, bearing scattered few- (2-6-) flowered heads; flowers greenish with 

 brown (2-^" long) ; sepals ovate-lanceolate, awl-pointed, rigid and strongly 

 nerved, the outer much shorter than inner ones, these a little shorter than the 

 triangular-ovoid beaked incompletely 3-celled brown pod ; ovary tapering into 

 a conspicuous style ; seeds large, oblong, delicately many-ribbed, with white 

 or often reddish appendages (l^'long). — Sphagnous swamps, New Jersey, 

 Pickering, C. E. Smith. August. 



Order 123. PONTEDEBIACEi:. (Pickerel-weed Family.) 



Aquatic herbs, with perfect more or less irregular flowers from a spathe ; 

 the petal-like 6-merous perianth free from the 3-celled ovary ; the 3 or 6 

 mostly unequal or dissimilar stamens inserted in its throat. — Perianth with 

 the 6 divisions colored alike, imbricated in 2 rows in the bud, the whole 

 together sometimes revolute-coiled after flowering, then withering away, 

 or the base thickened-persistent and enclosing the fruit. Anthers introrse. 

 Ovules anatropous. Style 1 : stigma 3-lobed or 6-toothed. Fruit a per- 

 fectly or incompletely 3-celled many-seeded pod, or a 1-celled 1-seeded 

 utricle. Embryo slender, in floury albumen. 



1. Pontederia. Perianth 2-lipped, its fleshy persistent base enclosing the 1-seeded utricle. 



Stamens 6. Spike many-flowered. 



2. Heteranthera. Perianth salver-shaped, withering-fugacious. Pod many-seeded. 



Stamens 3, unequal, of 2 forms. Spathe 1- few-flowered. 

 8- Sctiollcra. Perianth salver-shaped, regular. Stamens 3, alike. Spathe i-fiowered. 



