

THE CAYUGA FLORA. 105 



984. P. natans, L. var. prolixus, Koch, in the Inlet and north of Cay- 

 uga Bridge. A form of P. natans, with small leaves, resembling P. 

 Oakesianus, Robbins, grows in Cayuta L. 



985. P. Claytonii, Tuck. ( H -) 

 Abundant in the still shallow pools of Cayuga and Cayuta Lakes. 



Aug. -Sept. 



Only the specimens from Cayuta L. have the small leaves, as de- 

 scribed by Robbins. Cayuga L. specimens usually twice as long, 

 and the petioles usually as long as the blade. The embryo is coiled 

 1% times, not "transversely oval." 



986. P. Spirillus, Tuck. 



Cayuta L. east side, shallow water in sand ; rare. Aug. 



987. ? P. rufescens, Schrad. 



Myers Point, and pool two miles north. Summit Marsh ; scarce. 



In flower in Aug. and Sept. but not found in fruit. Dr. Robbins 



doubtfully referred them to P. rufescens rather than P. gramineus. 



988. P. lonchites, Tuck. (H. and Wright in C.) 

 Fall Cr. near the mouth. Dryden L. North of Cayuga Bridge 



Erie Canal and Seneca river; not common. Aug. -Sept. 



The Erie canal forms belong to Tuckerman's P. fluitans, Roth, 

 described in Silliman's Journal, LVII, p. 348. 



989. P. (species doubtful : possibly P. Illinoiensis, Morong,) was 

 found in the Inlet one season. 



990. P. amplifolius, Tuck. (H. and Wright in C.) 

 Cayuga and Cayuta Lakes. Dryden L. and Locke Pond. Aug. 

 Good specimens in the bayou at mouth of Fall Cr. Deep water 



forms are without floating leaves. 



991. P. gramineus, L. (H. and C.) 

 Cayuga L. near light-house and Myers Pt. Cayuta Lake. Sum- 

 mit Marsh, and elsewhere, extremely variable. Most of our forms 

 correspond most nearly to var. heterophyllus of 'Manual, which can- 

 not, however, be clearly defined as a variety, in this country, accord- 

 ing to Mr. Morong. 



992. P. Zizii, Mertens and Koch. (P. lucens, L., var. minor, Nolte, 

 of Man., p. 488.) (C. by Dr. Wright.) 



Fall Creek near the east bayou. Summit Marsh, usually in shal- 

 low water ; not rare, but fruits sparingly. Aug-Sept. 



993. P. lucens, L. (H. and C.) 

 West side of Cayuga L. and near Cayuga Bridge and Seneca 



River. Aug. -Sept. 



994. P. praelongus, Wulfen. (C. by Dr. Wright.) 

 S. W. part of Cayuga L. and occasional at the foot of the lake ; 



not common. Aug. -Sept. 



995. P. perfoliatus, L. (H. and C.) 

 Very abundant in shallow water from 1-4 meters deep, in Cayuga 



L., in ponds and creeks. July-Sept. 



996. P. perfoliatus, L., var. lanceolatus, Robbins. 



The leaves vary much in length, but some in Cayuga Outlet 

 should probably be referred to the var. lanceolatus. 



