102 NAIADACE^. 



floating achenes to other plants on the beaches. (Greek phyllon, leaf, 

 and spadix, a kind of inflorescence.) 



Flowering stems 1 ft. long or more, bearing 2 to 5 pistillate spadices 



1. P. Torveyi. 

 Flowering stems 2 or 3 in. long, bearing 1 pistillate spadix or rarely 2: leaves 

 more obviously S-nerved . ... .... ... 2. P. Scouleri. « 



1. P. Torreyi Wats. Torket's Ebl-grass. Eootstocks brittle, 

 leaves IJ to 2 ft. long, J to 1 line broad; flowering stems 1 ft. long 

 or more, bearing 2 to 5 pistillate spadices, each 1 to If in. long; 

 stamlnate spadices shorter and with shorter peduncles; mature fruit 

 2J lines long. 



Low tide limits to two fathoms below, from San Diego, Cleveland, 

 and San Pedro northward to Monterey, Seichell; Land's End, Gibbs; 

 and Russian Kiver, Dudley. 



2. P. Scouleri Hook. Pacific Ebl-grass. Very similar to the 

 preceding but the leaves rather broader, f to 2 lines wide; flowering 

 stems short, but 2 or 3 in. long, bearing but 1 pistillate sapdix, 

 rarely 2; fruits larger. 



Santa Barbara, Pacific Grove, and Russian Eiver ace. to Dudley; 

 Dillon's Beach, Baker, and northward to the mouth of the Columbia 

 River. 



6. NAIAS L. Naiad. 



Slender branching submerged plants with linear opposite spiny- 

 toothed leaves, which are seemingly whorled on account of the ones 

 crowded in the axils. Flowers unisexual, solitary in the axils. 

 Staminate flower consisting of a single sta,men enclosed in the bud in 

 a little membranous spathe. Pistillate flower consisting of a single 

 ovary and short style bearing 2 to 4 stigmas. Fruit a seed-like 

 nutlet. (Greek Naias, a water-nymph.) 



Sheathing base of the leaves entire or with few teeth . 1. N. marina. 



Sheathing base of the leaves with many minute teeth . . ,2.N. flexUis. 



1. N. marina L. Hollt-lkaved Naiad. Stems stout and 

 often armed with prickles twice as long as their breadth; leaves 

 broadly linear, with 6 to 10 spine-pointed teeth on each margin, the 

 broad sheathing base entire or with 1 or 2 teeth on each side; fruit 2 

 to 2| lines long, reticulated, tipped with a long persistent style; seed 

 reticulated, not shining. 



Clear Lake, Bolander. 



2. N.flexilis R. & S. Slender Naiad. Stems slender; leaves 

 narrowly linear, with 25 to 30 minute teeth on each margin, the 

 broad sheathing base with 5 to 10 small teeth on each side; fruit 1 to 

 2 lines long, nearly smooth; seed reticulated, shining. 



San Francisco Peninsula; Clear Lake. 



$. JUNCAGINACE/E. Arrow-grass Family. 



Marsh or sub-aquatic acaulescent herbs with radical rush-like or 

 grass-like leaves, and small perfect flowers in racemes or spikes, or 



