i6 



427 Greenei Morong 



428 hyperboreuin Laest. 



429 minimum Fries 



430 natans L. 



431 simplex Huds. 



432 angustifolium (Michx.) 



Engelm. 



433 multipedunculatmn Morong 



POTAMOGETONACEAE 

 Zostera 55 



434 latifolia Morong 



(Z. Pacifica Wats.) 



435 marina L. 



436 minor (Carol.) Nolte 



437 Oregana Wats. 



Phyllospaclix 56 



438 Scouleri Hook. 



439 Torreyi Wats. 



Potamogetoii 58 



440 alpinus Balbis 



(P. rufescens Schrad.) 



441 amplifolius Tuckerman 



442 confervoides Reichb. 



(P. Tuckermani Robbins) 



443 crispus L. 



444 Curtissii Morong 



445 diversifolins Raf. 

 (P. hybridus Michx.) 



446 mnltidenticnlatus Morong 



447 trichophyllus Morong 



448 Faxoni Morong 



449 filiformis Pers. 



450 occidentalis (Robbins) 



Morong 



451 Macounii Mcrong 



452 foliosns Raf. 



(P. panciflorus Pursh) 



453 Californicns Morong 



454 Niagarensis (Tuckerman) 



Morong 



455 Friesii Rupr. 



456 geminiparas (Robbins) Morong 



457 heterophyllus Schreb. 



458 graminifolius (Fries) 



Morong 



459 minimus Morong 



460 myriophyllus (Robbins) 



Morong 



461 Hillii Morong 



462 Illinoensis Morong 



463 interruptus Kitaibel 



464 lateralis Morong 



465 latifolius (Robbins) Morong 



466 lonchites Tuckerman 

 (P.fiuitans Roth) 



467 Noveboracensis Morong 



468 lucens L. 



469 Connecticutensis Robbins 



470 marinus L. 



471 mucronatus Schrad. 



472 Mysticus Morong 



473 natans L. 



474 Nuttallii C. & S. 



(P. Pennsylvanicus Cham.) 



475 Cayugensis Wiegand. 



476 Oakesianus Robbins 



477 obtusifolius Mert. & Koch 



478 pectinatus L. 



479 perfoliattis L,. 



480 Richardsonii A. Bennett 

 (P. perfoliatus var. lanceolatus) 



481 praelongus Wulf. 



482 pulcher Tuckerman. 



483 ptisillus L. 



484 Panonnitanus (Biv.) 



Morong 



485 polyphyllus Morong 



486 Sturrockii A. Bennett 



487 Robbinsii Oakes 



488 rutilus Wolfg. 



489 spathulaeformis (Robbins) 



Morong 



490 Spirillus Tuckennan 



491 Vaseyi Robbins 



492 Zizii Roth 



493 Methyensis (A. Bennett) 



Morong 



494 zosteraefolius Schum. 



Ruppia 59 



495 curvicarpa Aven Nelson 



496 maritima L. 



497 occidentalis Wats. 



498 pectinata Rydb. 



