The Flora of the Cayuga Lake Basin 93 



e. Scales thicker, more castaneous, less strongly nerved, persistent; spike- 

 lets subterete, subulate-tipped; plants annual. 

 /. Scales of the same side overlapping; rhachis broadly winged, inclosing 



the obovoid, obtuse or mucronate, achene. 6. C. ferax 



f. Scales of the same side distant ; rhachis thickened, narrowly winged ; 

 achene oblong, acute at both ends. 7. C. Engclmanni 



d. Scales 1.5 mm. long, mucronate, castaneous, overlapping ; rhachis with 

 broad wings which become separated as scales ; achenes broadly oval, 

 obtuse ; plants annual. 8. C. erythrorhizos 



c. Spikelets in solitary or sparsely umbellate heads, green ; plants wiry, cespitose, 

 perennial. 9. C. filiculmis, 



var. macilentus 



1. C. diandrus Torr. (C. diandrus of Cayuga Fl., in part.) 

 Sandy or mucky strands, also in meadows ; scarce. Aug.-Sept. 



Found only on the shores of Cayuga Lake and on the brackish marshes of the 

 Ontario plain : Renwick ; Canoga Marshes ; salt flats e. of Montezuma. 



N. B. to Minn., southw. to S. C. and Kans., including the Coastal Plain. 



A plant primarily of brackish situations ; more common in N. J. along the coastal 

 strip, and occurring in central N. Y. only where other brackish-marsh plants are found. 



2. C. rivularis Kunth. (C. diandrus of Cayuga FL, at least in part.) 



Damp sandy, gravelly, or marly strands and meadows, in more or less calcareous 

 soils ; not uncommon. Aug.-Sept. 



Marl strand, Spencer Lake; Six Mile Creek; marl spring, Coy Glen; Renwick 

 flats and shores ; marl spring above Forest Home ; Beaver Brook ; Asbury ; boggy 

 field, Benson Corners; gravelly strand and marl pool, Salmon Creek; Big Gully 

 Point ; Hibiscus Point ; canal n. of Cayuga ; Duck Lake. 



Me. to s. Ont. and Mich., southw. to N..»C, Mo., and Kans.; common on the 

 coastal plain of Mass. and N. J., a peculiar situation considering the distinctly cal- 

 careous distribution in the Cayuga Lake Basin. 



3. C. aristatus Rottb. (C. inflexus of Cayuga Fl.) 

 Sandy, gravelly, or muddy shores ; rare. Aug. 



Bar in Eddy Pond (Cascadilla Glen), 1884 (D.) ; shore of Cayuga Lake, Ren- 

 wick, 1894 {W . W. Rowlee & K. M. W.) ; gravelly shore by lighthouse, Ithaca; 

 Myers Point ; lake shore opposite Cayuga village. 



N. B. to B. C, southw. to Fla., Tex., Calif., and Mex. ; apparently rare on the 

 Atlantic Coastal Plain. 



The factors influencing the distribution of this species are not apparent. The 

 localities are more or less calcareous and two are somewhat saline. However, the 

 plant grows in the acid sands of eastern Mass. (though not in those of N. J.), 

 while along the coast it is distinctly not a plant of brackish marshes. 



4. C. strigosus L. 



Low open grounds, in sand or gravel, often with an admixture of clay or alluvium, 

 with little reference to the lime content of the soil ; common. Aug.-Sept. 



Me. to Ont. and Minn., southw. to Fla. and Tex., including the Coastal Plain. 



4a. C. strigosus L., var. compositus Britton. 



Usually in springy places on hillsides ; frequent. 



Near top of hill road n. of Coy Glen; Cayuga Heights, in several places; near 

 Indian Spring ; " a form is not uncommon on the brackish soil near the ' Deer-lick ' 

 west side of Cayuga marshes, bearing 5-flowered spikelets in narrow oblong rays " 

 (Z).), probably this variety. 



Mass. to Fla., La., and Iowa. 



