pontederiacejE. (pickebel-weed family.) 545 



1. PONTEDERIA, L. Pickerel-weed. 



Perianth funnel-form, 2-Iipped ; the 3 upper divisions united to form the 3- 

 lobed upper lip ; the 3 lower spreading, and their claws, which form the lower 

 part of the curving tube, more or less separate or separable down to the base : 

 after flowering the tube is revolute-coiled from the apex downwards, and its 

 fleshy-thickened persistent base encloses the fruit. Stamens 6 ; the 3 anterior 

 exserted on elongated filaments ; the 3 posterior (often sterile or imperfect) ^vith 

 very short filaments, unequally inserted lower down : anthers oval, blue. Ovary 

 3-celled ; two of the cells empty, the other with a single suspended ovule. Utri- 

 cle 1 -celled, filled with the single seed. — Stout herbs, growing in shallow water, 

 with thick creeping rootstocks, producing erect long-petioled mostly heart- 

 shaped leaves, and a 1 -leaved stem or scape, terminated by a spike of violet- 

 blue eplienieral flowers. Koot-leaves with a sheathing stipule within the petiole. 

 (Dedicated to Pontedera, Professor at Padua at the beginning of the last century.) 



1. P. cord^tEl, li. Leaves arrow-heart-shaped, blunt; spike dense, from 

 a spathe-like bract. — Var. angustif6lia (P. angustifolia, Pursh) has triangu- 

 lar-elongated and tapering leaves scarcely heart-shaped at the base. — Common. 

 July - Sept. — Calyx-tube in fruit crested with 6 toothed ridges. Upper lobe 

 of the perianth marked with a pair of small yellow spots. 



2. HETEB.ANTHEB.A, Kuiz & Pav. Mud-Plantain. 



Perianth salver-form with a slender tube ; the limb somewhat equally 6-parted, 

 ephemeral, soon withering or decaying. Stamens 3 ; the 2 posterior filaments 

 thickened in the middle and bearing ovate (yellow) anthers ; the other longer, 

 bearing a larger oblong or arrow-shaped (greenish) anther. Pod incompletely 

 3-celled, many-seeded. — Creeping or floating low herbs, in mud or shallow 

 water, with chiefly rounded long-petioled leaves, and a 1 -few-flowered spathe 

 bursting from the sheathing side or base of a petiole. Flowers blue or white, 

 in summer. (Name from erf pa, different, and dvOrjpd, anther.) 



1. H. renifdrmis, Ruiz & Pav. Leaves round-lddney-shaped ; ST^aihe 3-5- 

 flowered ; flowers white. — S. New York to Illinois, and southward. 



2. H. Iim6sa/, Vahl. Leaves oblong or lance-oblong, obtuse at both ends ; 

 spathe 1-flowered ; flowers blue. (Leptanthus ov&lis, Michx.) — W. Virginia to 

 Illinois, and southward. 



3. SCHOIiLEBA, Schreber (1789). Water Star-grass. 



Perianth salver-form, with 6 nearly equal lance-linear divisions on a very long 

 thread-like tube. Stamens 3, with similar oblong-arrow-shaped anthers (or 

 rarely a fourth which is abortive) : filaments nearly equal, awl-shaped. Pod 

 oblong, invested by the withered perianth, l-celled with 3 projecting parietal 



placentas, many-seeded A grass-like herb, like a Pondweed, growing wholly 



under water, only the (small pale-yellow) flowers reaching the surface ; the 

 slender branching stems clothed with linear translucent sessile leaves, and 

 bearing a terminal 1-flowered spathe : in summer. (Named after one Scholler, 

 a German botanist.) 



1. S. graminea, Willd. (Leptanthus, Mc/jx.) — In streams: common. 

 35 



