4 MINNESOTA BOTANICAL STUDIES. 



lished itself, and here and there patches of sphagnum the size 

 of a dinner-plate were floating on the surface of the water. 

 Three species of sphagnum were present, but these have not 

 yet been specifically determined. In the channel through which 

 the pond drains into lake Whitman, as noted above, Typha lati- 

 folia Linn, (cat-tail) was observed, but elsewhere it was want- 

 ing in this pond, though a very common aquatic of the region 

 in general. 



Tegetation of Ballard's atoll. The plants established upon 

 the atoll itself were, however, very different, and in the case of 

 one plant highly remarkable. When seen from the shore, early 

 in July, the atoll was aflame with the crimson flowers of Sar- 

 racenia purpurea Linn. — the side-saddle flower, or as more 

 commonly termed in Minnesota, the pitcher-plant. Mingled 

 with the red, and scarcely less abundant, were the white and 

 cottony inflorescences of three different species of Eriophorum 

 (cotton-grass). A careful examination of the atoll, close at 

 hand, showed that the following plants were established upon 

 it: 



Scheuchzeria palustris Linn. 



Carex tenuiflora Wahl. — Sedge. 



Carex tenella Schkr. — Sedge. 



Carex intumescens Rudge. — Sedge. 



Eriophorum polystachion Linn. — Cotton-grass, 



Eriophorum gracile Koch. — Cotton-grass. 



Eriophorum vaginatum Linn. — Cotton-grass. 



Pogonia ophioglossoides (Linn.)Ker. — Adder's tongue orchis. 



Limodorum tuberosum Linn. — Purple orchis. 



Lyonia calyculata (Linn.) Reich. 



Kalmia glauca Ait. — Pale laureJ. 



Andromeda polifolia Linn. — Andromeda. 



Oxycoccus oxycoccus (Linn.) MacM. — Small cranberry. 



Menj^anthes trifoliata Linn. — Buckbean. 



Sarracenia purpurea Linn. — Pitcher- plant. 



In addition to these and forming a matrix upon which they 

 had d eveloped were the same three undetermined species of 

 sphagnum which had been found in small patches outside of 

 the atoll. The general texture of the atoll was loose so that 

 one standing anywhere upon it soon sank into the soft and 

 spongy moss up to the knees. Compared with that of the 

 surrounding pond it will be seen that the atoll vegetation 

 is entirely distinct. The most notable plant, from the point of 

 view of the plant geographer, is Kalmia glauca Ait. This lo- 



