The Flora of the Cayuga Lake Basin 95 



c. Upper sheath loose, with white scarious summit ; plants low, perennial, with 

 matted rootstocks ; tubercle narrow, saucer-shaped, conical-beaked. 



2. E. olivacea 

 c. Upper sheath close, not scarious, often dark-margined. 



d. Plants tufted, annual ; tubercle broad, depressed. 3. E. obtusa 



d. Plants not tufted, perennial, with creeping rootstocks ; tubercle narrow, ovate. 



4. E. palitstris 

 b. Achenes triangular or turgid, not smooth and glossy; styles 3-cleft. 



c. Achenes coarsely reticulated, the transversely elongated areoles in several 

 vertical rows; culms capillary, 3-10 cm. high; plants perennial, forming dense 

 mats. 5. E. aciadaris 



c. Achenes minutely cellular-reticulated, the areoles nearly isodiametric. 



d. Tubercle definitely articulated with the achene ; culms not rooting at tip. 

 e. Tubercle depressed ; culms wiry, 4-angled, erect ; plants perennial, with 



creeping rootstocks. 6. E. capitata 



e. Tubercle conical-subulate; culms striate-grooved, recurved; plants annual, 

 tufted. 7. E. intermedia 



d. Tubercle continuous with the achene, pyramidal ; culms stout, recurved, 

 rooting at tip (3-12 dm. long). 8. E. rostellata 



1. E. quadrangulata (Michx.) R. & S. (See Rhodora 27:37. 1925.) 



In shallow water along the borders of ponds, perhaps influenced by saline con- 

 ditions ; rare. Aug. 



Duck Lake (K. M. W ., A. J. E., & L. E. Randolph). [Elsewhere reported from 

 N. Y. State only from Westchester Co. (Mead), Lake Neahtowantah, Oswego Co. 

 {Coville, Rowlee, Sheldon), Paddy Lake, Oswego Co. {Wibbe), and outlet of 

 Oneida Lake (A. H. Curtiss in Gray's Man., ed 5).] 



Mass. to Ont. and Mich., southw. to Ala. and Tex., including the Coastal Plain ; 

 also in warmer parts of Am. 



2. E. olivacea Torr. 



Wet peaty and mucky acid soil, in sandy or gravelly regions ; rare. Aug. 

 Summit Marsh ; Pout Pond marsh ; Slayton Pond. 



N. S. to Ont. and Mich., southw. to Pa., S. C, and Ohio, including the Coastal 

 Plain. 



3. E. obtusa (Willd.) Schultes. 



Shores, ditches, and exsiccated places, in a great variety of soils ; common, and 

 generally distributed. June-Aug. 



N. S. to Ont., southw. to Fla. and Tex., including the Coastal Plain; also from 

 B. C. to Oreg. 



E. ovata (Roth) R. & S. has not been found here, but Dudley's no. 1019 strongly 

 suggests this. 



4. E. palustris (L.) R. & S. 



Form a. — Very slender ; culms 0.3-1 mm. thick. 



Sandy or silty shores and crevices of rocks in ravines, probably in limy soils ; 

 frequent. June 20-Aug. 



Enfield Glen; Dwyer Pond; lake shore at Renwick; near Townley Swamp; 

 near Asbury; lake shore at Utt Point and Big Gully Point; marl ponds at Hibiscus 

 Point ; Slayton Pond. 



Form b. — Culms 1-2.5 mm. thick. 



Marly brook, e. end of Dryden Lake; deep water, n. end of Chicago Bog. 



Form c. — Culms 2.8-3.3 mm. thick, almost or quite as broad as the spikelet ; plants 

 very tall. 



Shallow water, Summit Marsh. 



