liljsa NAIADACE^ 673 



ZANNICHELL1A 



lower wingless and laterally toothed at the summit, Seed with 

 membranous testa and straight narrow embryo. 



L. subulata Humb. & Bonpl. 1. c. Leaves 6 inches to 2 feet long or 

 more, 1-2 lines thick: heads crowded, 6-12 lines long, on scapes shorter 

 than the leaves : staminate bracts narrowly oblong, obtuse, }<£ line long, 

 twice longer than the anthers : radical fruits 3 lines long, the filiform styles 

 often nearly as long as the scapes : upper fruits elliptical, acute, somewhat 

 smaller. In shallow water or mud, Vancouver Island to South America. 



5 ZANNIOHfiLLIA L. Sp. 969. 



Very slender immersed branching aquatic herbs with filiform 

 flattened mostly opposite leaves, with small free membranous 

 stipules,and inconspicuous monoecious flowers in axillary clusters. 

 Staminate flowers of a single naked stamen with elongated fila- 

 ment and 2-celled anther. Pistillate flowers usually in the same 

 axils, of 2-5 sessile or shortly stipitate ovaries in a membranous 

 cup-shaped perianth or spathe: style short, with peltate stigma. 

 Ovule solitary, suspended. Fruit an obliquely oblong coriaceous 

 nutlet, somewhat compressed, beaked by the short style. Seeds 

 with membranous testa. Embryo slender, the attenuate cotyle- 

 donary end bent into a coil. 



Z. palustrls L. Sp. 969. Stems 2 inches to 2 feet long, branching and 

 leafy : leaves about 3 inches long, % line or less wide, thin, 1-nerved : fruit 

 sometimes incurved, often more or less toothed on the back. 1-13^ lines 

 long, about twice longer than the style, usually becoming shortly stipitate 

 and often also pedunculate. In fresh-water ponds and slow streams, 

 throughout most parts of the World. 



6 RUPPIA L. Sp. 127. 



Slender branching submersed herbs growing in brackish or salt 

 water, with filiform or capillary alternate leaves, with broadly 

 sheathing bases, and small perfect flowers enclosed in the base of 

 the leaves. Flowers on a capillary spadix-like peduncle, without 

 perianth, consisting of 2 sessile antners, each with 2 separate cells, 

 attached by the back to the peduncle, having between them sev- 

 eral pistillate flowers in 2 sets on opposite sides of the rachis, the 

 whole at first enclosed in the base of a leaf, the peduncle at length 

 long exserted and bearing the ovaries in 2 clusters at the end. 

 Ovaries at first sessile, with nearly sessile depressed stigmas and 

 solitary suspended camplytropous ovules. Fruit obliquely ovoid, 

 very shortly beaked, on elongated slender stipes, hard and drupe- 

 like. Seed with membranous testa. Embryo ovoid, with short 

 cotyledon and short lateral plumule. 



R. maritima L. Sp. 157. Stems elongated, filiform, 6-20 inches or 

 more high, leafy : leaves 2-4 inches long. % 'i ,ie wide, with usually broadly 

 dilated bases: flowers 2-8, in a short close spike: fruiting peduncle 3-6 

 inches long, contorted : fruit \% lines long, the stipe 1-12 lines long. In 

 brackish or salt pools along the coast. Alaska to California, and in most 

 parts of the world. 



