566 NAIADACE^E. (PONDWEED FAMILY.) 



(N. major, All.) Marshes and salt-springs of western N. Y. and Mich. Teeth 

 of one or more brownish cells upon a many-celled base. (Eu.) 



Var. grcilis, Morong. Internodes long (1-3') and nearly naked, with 

 only a few teeth above ; leaves very narrow, the dilated base also toothed ; 

 fruit smaller. Canoga marshes, western N. Y. ; also in Fla. 



Var. recurv&ta, Dudley. Stems short, inclined to be dichotomously 

 branched, recurved-spreading ; leaves usually recurved, the teeth prominent, 

 the dilated base with a projecting tooth each side. Cayuga marshes, N. Y. 



2. N. fl&xilis, Rostk. & Schmidt. Stems usually very slender; leaves 

 very narrowly linear (1-1' long), very minutely serrulate; fruit \y long, 

 narrowly oblong ; seeds lance-oval, smooth and shining. Ponds and slow 

 streams, N. Scotia to S. C., Iowa and Minn. Teeth on the margins of the 

 leaves 1-celled. (Eu.) Var. ROBUSTA, Morong. Stem stout, few-leaved, 

 sparsely branching, elongated ; leaves flat, abruptly acute. E. Mass., Mich., 

 and Tex. ^ 



3. "N. Indica, Cham., var. gracillima, A. Br. Branches alternate ; 

 leaves very narrowly linear, nearly capillary, straight, serrate, the rounded lobes 

 of the sheathing base spinulose-ciliate ; fruit linear, impressed-dotted between the 

 numerous ribs. Mass, to Penn., west to Ind. and Mo. Teeth of 3 cells each. 



ORDER 127. ERIOCAULE^. (PIPEWORT FAMILY.) 



Aquatic or marsh herbs, stemless or short-stemmed, with a tuft of fibrous 

 roots, a cluster of linear and often loosely cellular grass-like leaves, and 

 naked scapes sheathed at the base, bearing dense heads of monoecious or 

 rarely dioecious small 2 - 3-merous flowers, each in the axil of a scarious 

 bract; the perianth double or rarely simple, chaffy; anthers introrse; the 

 fruit a 2-3-celled 2 3-seeded capsule; seeds pendulous, orthotropous ; 

 embryo at the apex of mealy albumen. Chiefly tropical plants, a few 

 in northern temperate regions. 



1. Eri oca ul 011. Perianth double, the inner (corolla) tubular-funnel-form in the staminate 



flowers ; stamens twice as many as its lobes (4). Anthers 2-celled. 



2. P&epalanthus. Perianth as in the last ; stamens only as many as the corolla-lobes (3). 



Anthers 2-celled. 



3. Lachnocaulon. Perianth simple, of 3 sepals. Stamens 3, monadelphous below. 



Anthers 1-celled. 



1. ERIOCAtlLON, L. PIPEWORT. 



Flowers monoecious and androgynous, i. e. both kinds in the same head, either 

 intermixed, or the central ones sterile and the exterior fertile, rarely dioecious. 

 Ster. Fl. Calyx of 2 or 3 keeled or boat-shaped sepals, usually spatulate or 

 dilated upward. Corolla tubular, 2 - 3-lobed, each of the lobes bearing a black 

 gland or spot. Stamens twice as many, one inserted at the base of each lobe 

 and one in each sinus ; anthers 2-celled. Pistils rudimentary. Fert.FL Calyx 

 as in the sterile flowers, often remote from the rest of the flower (therefore per- 

 haps to be viewed as a pair of bractlets). Corolla of 2 or 3 separate narrow 

 petals. Stamens none. Ovary often stalked, 2 - 3-lobed, 2 - 3-celled ; style 1 ; 

 stigmas 2 or 3, slender. Capsule membranaceous, loculicidal. Leaves mostly 

 smooth, loosely cellular and pellucid, flat or concave above. Scapes or pedun- 



