4UO HVDliOCHARIDACE^E. (KROG's-BIT FAMILY.) 



by the prolonged calyx-tube, which varies iu length according to the depth of 

 the water. (Name from e/\.w8rjs, marshy.) 



1. E. Canadensis, Michx. Leaves in 3's or 4's, or the lower opposite, 

 varying from linear to oval-oblong, minutely serrulate ; stamens 9 in the sterile 

 flowers, 3 or 6 almost sessile anthers in the fertile. (Anacharis Canadensis, 

 Planchon.) Slow streams and ponds, common. July. 



2. VALLISNERIA, L. TAPE-GRASS. EEL-GRASS. 



Flowers strictly dioecious ; the sterile numerous and crowded in a head on a 

 conical receptacle, enclosed in an ovate at length 3-valved'spathe which is borne 

 on a very short scape ; stamens mostly 3. Fertile flowers solitary and sessile 

 in a tubular spathe upon an exceedingly lengthened scape. Perianth (calyx) 

 3-parted in the sterile flowers; in the fertile with a linear tube coherent with 

 the 1 -celled ovary, but not extended beyond it, 3-lobed (the lobes obovate) ; 

 also 3 linear small petals. Stigmas 3, large, nearly sessile, 2-lobed. Ovules 

 very numerous, scattered over the walls, orthotropous. Fruit elongated, cylin- 

 drical, berry-like. Stemless plants, with long linear grass-like leaves, wholly 

 submerged. The staminate clusters being confined to the bottom by the short- 

 ness of the scape, the flower-buds themselves break from their short pedicels 

 and float on the surface, where they shod their pollen around the fertile flow- 

 ers, which are raised to the surface by sudden growth at the same time ; after- 

 wards the thread-form scapes (2-4 feet long) coil up spirally, drawing the fruit 

 underwater to ripen. (Named for Ant. Valllsneri, an early Italian botanist.) 



1. V. spiralis, L. Leaves linear, thin, long and ribbon-like (1 -6 long), 

 obscurely serrulate, obtuse, somewhat nerved and netted-veiued. Common iu 

 slow waters, N. Eng. to Fla., west to Minn, and Tex. 



3. LIMNOBIUM, Richard. AMERICAN FROG'S-IUT. 



Flowers dioecious, (or monoecious?) from sessile or somewhat peduncled 

 spathes ; the sterile spathe 1 -leaved, producing about 3 long-pedicelled flowers ; 

 the fertile 2-leaved, with a single short-pedicelled flower. Calyx 3-parted or 

 cleft ; sepals oblong-oval. Petals 3, oblong-linear. Filaments entirely united 

 in a central solid column, bearing 6-12 linear anthers at unequal heights; 

 there are 3-6 awl shaped rudiments of stamens in the fertile flowers. Ovary 

 6-9-celled, with as many placentae in the axis, forming an ovoid many-seeded 

 berry in fruit; stigmas as many as the cells, but 2-parted, awl-shaped. A 

 stemless perennial herb, floating in stagnant water, proliferous by runners, 

 with long-petioled and round-heart-shaped leaves, which are spongy-reticulated 

 and purplish underneath ; rootlets slender, hairy. Sterile flowers rather small ; 

 the fertile larger; peduncle nodding iu fruit. Petals white 1 (Name from 

 A/yUj>6/3jos, I/ring in pools.) 



1. L. Spongia, Richard. Leaves 1 -2' long, faintly 5-nerved ; peduncle 

 of sterile flower about 3' long and filiform, of the fertile only 1' long and stout. 

 Stagnant water, N. J. to Fla. ; also L. Ontario, 111., and Mo. 



ORDER 109. BUKMANNIACEyE. (BURMANNIA FAMILY.) 



Small annual herbs, often with minute and scale-like leaves, or those at the 

 root yrass-like : the flowers perfect, with a 6-cleft corolla-like perianth, the 



