Climate of Middle Illinois. 



75 



Tricuspis, of the exclusively North American genera reach the Rocky 

 Mountains or the Pacific coast 35: Lechea, Callirhoe, Ptelea, Floerkea, 

 Amorpha, Petalostemon, Apios, Baptisia, Proserpinaca, Heuchera, Gaura, 

 Thaspiom, Liatris, Chrysopsis, Polymnia, Silphiura, Echinacea, Rudbeckia, 

 Lepachys, Krigia, Troximon, Dodecatheon, Aphyllon, Chelone, Pentstemon, 

 Monarda, Physostegia, Pycnanthemum, Hydrophyllum, EUisia, Amsonia, 

 Dirca, and Bouteloua. 



Of our genera restricted to the Western Hemisphere occur with 

 single species in Mexico or South America 12: Ceanothus, Oenothera, Par- 

 thenium, Heliopsis, Helenium, Seymeria, Gerardia, Castilleja, Asclepias, 

 Oxybaphus and Echinodorus, 8 are chiefly South American and partly 

 North American: Asimina, Cuphea, Kuhnia, Actinomeris, Helianthus, 

 Dysodia, Conobea and Tradescantia. 



A number of genera are commou to North America and Eastern 

 Asia or the Himalayas, of which 26 are represented in our flora amongst 

 which is Phryma. Genera with one species in each continent are: Meui- 

 spermum, Jeffersonia, Caulophyllum, Podophyllum, Nelumbium, Negundo, 

 Crypotaenia, Penthorum, Hamamelis, Saururus, Symplocarpus, and of our 

 two species of Osmorrhiza one is found in Eastern Asia; the 12 species of 

 Dicentra are equally divided, 6 for each continent. Chiefly Asiatic are: 

 Ampelopsis, Amphicarpaea, Hydrangea, Arissem a. Chiefly American: 

 Claytonia, Mitella, Archeniora, Triosteum, Nabalus (now united with 

 Prenanthes), Lophanthus, Phlox, Uvularia and Trillium. 



Many tropic genera are represented by one or a few species in North 

 America, of which we find in our flora the following: 



N.B. * Means that the genus is a large one with 50 and uiore 

 species, f means that the genus is chiefly South American. 



Polanisia. 



Mollugo. 

 *Zanthoxylum. 

 *Crotalaria. 

 *Psoralea. 

 *Tephrosia. 

 *Desmodium. 

 ■*=Cassia. 



Desmanthus. 

 *Phaseolus. 

 *Impatiens. 



Ammannia. 



Sicyos. 

 *Spermacoce. 



Cephalanthus. 

 *Vernonia. 

 t*Eupatorium. 



Eclipta. 

 fAmbrosia. 



Erechtites. 

 t*Lobelia. 



Gaylussacia. 

 *Tecoma. 

 *Diospyros. 

 *Plantago. 



llysanthes. 

 *Ruellia. 

 ^Verbena. 

 *Lippia. 

 ■|*Ipomoea. 

 t*Solanum. 

 *Physalis. 



Datura. 

 *Aristolochia. 



Phytolacca. 

 *Euphorbia. 

 •*Acalypha. 

 *Laportea. 

 *Pilea. 



Boehmeria. 

 *Celtis. 



Hypoxis. 

 *Habenaria. 

 Spiranthes. 



Liparis. 

 *Dioscorea. 



Pontederia. 

 *Cyperus. 



Fimbristylis. 

 *Scleria. 



Leersia. 

 *Vilfa. 

 *Sporobolus. 

 *Muhlenbergia. 

 *Panicum. 



Cenchrus. 

 *Andropogon. 



Cbrysopogon. 

 ■fAdiantnm. 



Pteris. 



Azolla. 



