ECOLOGY OF ISLE ROYALE. 233 



118. Potamogeton perfoliatus L. Clasping leaved Pond-weed. Mar- 

 gin of Sumner Lake. 



119. Potamogeton heterophyllus. Sclireb. Washington Creek. 



120. Potamogeton hillii (?) Hill's Potamogeton. Margin of Sumner 

 Lake. 



121. Potamogeton pectinatus L. Margin of Sumner Lake. 



122. Naias flewilis Willd. Slender Naias. Shallow water at head of 

 Bock Harbor. 



Scheuchz&riaceae — Arrow-Grass Family. 



123. TriglQchin maritlma L. Bog margin of Sumner Lake. Not 

 abundant. Ill, 5. 



Vallisneriaceae — Tape-Grass Family. 



124. Yallisneria spiralis L. Tape-Grass, Eel-Grass. Shallow water 

 at head of Rock Harbor. 



Graminae — Grass Family. 



125. Panicumv xantTiopTiysum A. Gray. Dry rocky ridges, and rocks 

 "with little soil. 



126. Agrostis hyemalis (Walt.) B. S. P. Rather dry ground. 



127. Calamagrostis canadensis (Michx.) Beauv. Rock pool margins, 

 Scovill Point, IV, 1. Creek margin upper end of Rock Harbor, III, 3. 

 Wet places generally. 



128. Trisettmi suispicatum (L) Beauv. Common in rock crevices 

 and dry places. Rock shore where little soil is present, where it occurs 

 as the pioneer grass. I, 1; V, 2. 



129. Phragmites phragniites (L) Karst. Washington Creek. 



130. Poa pratensis L. A dry ground form. Island in Rock Harbor, 

 III, 1. 



131. Panicularia canadensis (Michx.) Kuntze. Upper end of bog at 

 •end of Siskowit cabin trail. V, 5. 



132. Panicularia elongata (Torr.) Kuntze. Margin of Siskowit cabin 

 trail bog. V, 5. 



133. Fescuta ovina L. Rock crevices and on thinly soil-covered rocks. 

 I, 2; V, 2. 



Cyperaceae — Sedge Family. 



134. Eleocharis palustris (L) R. & S. In shallow water at upper 

 •end of Siskowit cabin trail. V, 5. 



135. Eleocharis palustris glaucescens (Willd.) A. Gray. (?) Wet 

 part of island in Tobin Harbor. 



1361 Scirpus caespitosus L. Margin of Forbes Lake, II, 5, Rock 

 pools, Scbvill Point. IV, 1. 



137. Scirpus cyperinus (L) Kunth. Low ground along "Island 

 mine" road, head of Siskowit Bay. 



138 Eriophorum alpinum L. Alpine Ootton-Grass. Most common 

 ^'cotton-grass" on the island. Common in all the bogs. II, 2; III, 5. 



139. Eriophorum vaginatum L. Sheathed Cotton-Grass. Sphagnum 

 bogs. V, 11; III, 4; V, 5. 

 31 



