No. 50.] 181 



Orontium, L. Golden Club, Floating Arum . 

 aquaticum, L. In shallow water. May. 



Acorus, L. Calamus, Sioeet Flag . 



calamus, L. Wet meadows and swamps . May-June . 



Order TYPHACEtE. The Cat-tail Tribe. 



Typha, L. Cat-tail, Reed Mace . 



latifolia, L. Borders of swamps and rivers . June-July . 

 angustifolia, L. With the preceding. 



Sparganium, L. Burr Reed. 



ramosum, L. In shallow ponds and streams . June . 



simplex, Smith. S. americanum, Nutt. Borders of streams. July. 



Order FLUVIALES. 



Najas, L. 



canadensis, Michx. Ponds and slow-flowing water . July . 



Zostera, L. Grasswrack. 



marina, L. Seashore and salt-water bays . 



Zannichellia, L. Triple-headed Pondweed . 



palustris, L. Z. intermedia, Torr. Ditches and shallow ponds ; 

 most common in brackish water . July . 



Ruppia, L. 



maritima, L. Salt-water ditches . July. 



Potamogeton, L. Pondweed . 



natans, L. Ponds and slow-flowing water . July . 



heterophyllus, Schreb.? P. fluitans of American botanists. Ponds, 

 &c. 



diversif olius, Bart. Flowing water . July- August. 



perfoliatus, L. Flowing water . July . 



praelongus, Wulff. P. luceus of American botanists. Slow-flowing 

 deep water . July- August . 



compressus, L. P. zosteraefolius, Schum.? Flowing water. July. 



gramineus, Michx. P. pauciflorus, Pursh. Small streams. July- 

 August . 



pectinatus, L. P. marinus, Michx. Fresh and brackish water . 

 July . 



