PAPERS ON BIOLOGY AND AGRICULTURE 



101 



to the vernal flora. The list of aestival species is based 

 on fairly thorough collections, one set of which has been 

 deposited with the herbarium of the Field Museum of 

 Natural History. Facilities for spring collecting, how- 

 ever, were unfortunately not so good, and the vernal 

 species accordingly are based largely on field identifica- 

 tions and partial collections only. The writer also wishes 

 frankly to disclaim any dogmatic certainty regarding a 

 few of the more difficult groups; notable here are the 

 sedges. Gray's Manual (seventh edition) was used 

 throughout. 



The writer's thanks are due to Professors Cowles and 

 Fuller of the University of Chicago for encouragement, 

 assistance, and generous provision of facilities ; to Pro- 

 fessor Conrad of Grinnell College for help in checking 

 over identifications ; and to the Illinois State Park Board 

 for permission to collect in the Park. 



Pohipodiacrae 



Polypodium vulgare 



Adianturu pedatum 



Pteris aquilina 



Pellaea atropurpurea 



Asplenium filix-femina 



Polystichum acrostichoides 



Aspidium thelypteris 



Aspidium marginale 



Aspidium spinulosum 



Cystopteris bulbifera 



Cystopteris fragilis 



Woodsia ilvensis (fide Cowles) 



Onoclea sensibilis 



Onoclea struthiopteris 

 Osmimdaceae 



Osmunda regalis 



Osmunda claytoniana 



Osmunda cinnamomea 

 Ophioglossaceae 



Botrychium virginianum 

 Equisetaceae 



Equisetum arvense 



Equisetum hyemale 

 Selagincllaccae 



Selaginella rupestris 

 Taraceae 



Taxus canadensis 

 Pinaceac 



Pinus strobus 



Thuja occidentalis 



Juniperus virginiana 



TypTxaceae 

 Typha latifolia 



Alismacecte 



Sagittaria latifolia 

 Alisma plantago-aquatica 



Gramineae 



Andropogon scoparius 

 Andropogon furcatus 

 Panicum capillare 

 Panicum scribnerianum 

 Echinochloa crus-galli 

 Setaria glauca 

 Leersia virginica 

 Muhlenbergia sylvatica 

 Muhlenbergia mexicana 

 Phleum pratense 

 Agrostis hiemalis 

 Cinna arundinacea 

 Eragrostis trichodes 

 Eragrostis pectinacea 

 Poa pratensis 

 Bromus purgens (?) 

 Elymus australis (?) 

 Elymus virginicus 

 Hystrix patula 

 Arundinaria tecta 



Cyperaceae 



Scirpus atrovirers 

 Carex stellulata 

 Carex laxiflora 

 Carex lupulina (?) 

 Carex grayi 



