NAIADA-CEiE. 385 



simple. Fruit a little nut or indehiscent capsule. Seed with- 

 out albumen. — Water plants, with simple cellular leaves and 

 membranous stipules. Flowers inconspicuous, often in termi- 

 nal spikes. 



1. ZOSTERA. /ymw.— Grasswrack. 



(From the Greek ^wirTTjp, a girdle or ribbon, which the leaves sometimes fe- 

 jiemble.) 



Stamens and pistils separated, seated in 2 rows upon one 

 side of a flat spadix. Anthers ovate, sessile. Pistils alterna- 

 ting with the anthers, ovate. Style subulate. Stigmas 2. Utri- 

 cle with 1 seed, bursting irregularly. 



Z. marina Linn. : stem roundish ; leaves entire, somewhat 3-nerved. 



Muddy shores. Mass. and N. Y. to Car. Aug. %. — Stem terete, flexuous, 

 throwing out roots from the joints. Leaves very long and narrow. Spadix 

 linear, arising from a sheathing portion of the leaf. Flowers green ; pistils and 

 anthers alternate. This plant is used in Europe for packing glass and earthen- 

 ware. Beds are also sometimes made of it. Common Grasswrack. 



2. CAULINIA. PF/Z^^.— Caulinia. 



{In honor of F. Cavolini ; a Neapolitan botanist.) 



Monoecious. Perianth none. Sterile Fl. Anther nearly 

 sessile. Fertile Fl, Style filiform. Stigmas 2. Fruit capsu- 

 lar, 1 -seeded, 



1. C. fragilis Willd. : leaves ternate or opposite, linear-subulate, re- 

 curved, aculeate-dentate, rigid. 



In water. Penn. Aug. ®. — Stem long, submerged. Flowers small. 



Brittle Caulinia. 



2. C. Jlexilis Willd. : leaves whorled in sixes, linear, dennculate near 

 the apex, spreading, Najas Canadensis Mich. 



Ponds* and ditches. Can. to Car. July, Aug. Q. — Stem 6 — 18 inches long, 

 submerged, dichotomously branched, jointed. Flower solitary, axillary, sessile. 



Bending Caulinia. 



3. ZANNICHELLIA. i>iwi.— Horned Pondweed. 

 (In honor of John Jerome Zannvchelli ; a Venetian apothecary and botanist.) 



Monoecious. Sterile Fl, Perianth none. Stamen 1. Fila- 

 ment slender. Fertile Fl. Perianth cup-shaped. Pistils 

 2 — 4, tapering into a short style. Stigma large and peltate. 

 Finiit on a short stipe, coriaceous. 



Z. palustris Linn. Z. intermedia Torr. Comp. 



Ditches and stagnant waters. Can. to Virg. July, Aug. (I). — Stem long, 

 filiform, much branched. Leaves opposite, linear, entire. Flowers axillary, 

 from a membranaceous cup-shaped perianth or involucre, small. Stamen 

 longer than the pistils. Anther large, 4-celled, {Hook.) 2-celled, (Torr.) Stig- 

 ma entire. Fruit a little incurved, sometimes toothed on the back. 



Horn Pondweed. 



17 



