1920.] NATURAL SCIENCES OF PHILADELPHIA. 



Peramium pubescens x X X 



repens x X o 



Serapias helleborine (viridi- 



flora)....... ^ •, X X 



Malaxis unifolia X X X x 



Liparis liliifolia x X X X x 



loeselii x x X X x o 



Aplectrum hyemale (spica- 



tum) X X X X X 



Tipuharia unifolia x x X X 



Corallorrhiza maculata x X x . 



odontorhiza x X x x 



wisteriana . x X x 



111 



