The Flora of the Cayuga Lake Basin 137 



23. PONTEDERIACEAE (Pickerel- weed Family) 



a. Plant erect; flowers blue; perianth 2-lipped; stamens 6; utricle 1-seeded; leaves 

 cordate-ovate. 1. Pontederia 



a. Plant floating, or prostrate on mud; flowers yellow; perianth salver- form; stamens 

 3 ; capsule many-seeded ; leaves linear. 2. Heteranthera 



1. Pontederia L. 

 1. P. cordata L. Pickerel- weed. 



In shallow or deep water along lake and stream margins, in mucky neutral or 

 acid soil, rarely in gravel ; scarce. July 20-Aug. 



Cayuta Lake ; Inlet and Cayuga Marshes ; Duck Lake. 



N. S. to Minn., southw. to Fla. and Tex., including the Coastal Plain. 



2. Heteranthera R. & P. 



1. H. dubia (Jacq.) MacM. (Schollera graminifolia of Cayuga Fl.) Water Star 

 Grass. 



Slow streams, marshes, and on mud, if not too acid; locally abundant. July-Aug. 



Abundant in the marshes of Cayuga Lake; rare elsewhere. 



Que. and w. N. E. to Oreg., southw. to Fla. and Mex. ; rare or absent on the 

 Atlantic Coastal Plain. Found also in Cuba. 



24. JUNCACEAE (Rush Family) 



a. Capsule many-seeded ; seeds minute ; foliage never hairy. 1. Juncus 



a. Capsule containing 3 large seeds ; foliage with more or less arachnoid pubescence. 



2. Luzula 

 1. Juncus (Tourn.) L. 



a. Leaves reduced to the sheath only ; cyme appearing lateral, the solitary involucral 

 leaf resembling a continuation of the culm. 

 b. Stamens 3 ; plant green. 

 c. Flowers 1.7-2.4 (2.6) mm. long; perianth soft, slightly spreading; cyme small, 

 densely crowded ; culms stout, with pale sheaths. [/. effusus, 



var. compactus] 

 c. Flowers (2.3) 2.5^1.2 mm. long; perianth firmer; cyme loose. 



d. Sepals rarely exceeding either the petals or the capsule, 2.5-3.5 mm. long, 

 not spreading, not contrasting in color with the capsule; culms 2—4.5 mm. 

 in diam. just above the pale basal sheaths, not sulcate. 



1. /. e., var. solutus 

 d. Sepals exceeding both the petals and the capsule, 2.8-4.2 mm. long, more 

 rigid and more spreading, usually contrasting in color with the darker cap- 

 sule ; culms 1-3.5 mm. in diam. just above the blackish basal sheaths, 

 striate or sulcate. la. /. e., var. Pylaei 



b. Stamens 6; plant glaucous (capsule very dark, subacute.) 2. /. inflexus 

 a. Leaves with a well-developed blade ; inflorescence terminal. 



b. Flowers borne singly in the cyme, not in heads ; leaves flat and grass-like, or at 

 least deeply channeled above, 

 c. Inflorescence more than half the height of the very low plant; flowers scattered 



along the loose forking branches. 3. /. bufonins 



c. Inflorescence very much less than half the height of the taller plant. 

 d. Uppermost leaf usually at or above the middle of the stem; perianth parts 

 appressed, obtuse. 

 e. Anthers three to four times as long as the filaments ; perianth dark, nearly 

 equaling the lighter subellipsoid capsule; bracts shorter than the 

 inflorescence. 4. /. Gerardi 



