United States National Museum, and University of Pennsylvania, and from the following 

 publications: 



Sarraceniaceae, by John M. Macfarlane. Engler's Pflanzenreich, vol. iv. no, 1908. 



The American pitcher-plants, by Roland M. Harper. Journal of the Elisha Mitchell Scientific 



Society, vol. 34, p. no, 1918. 

 The biochemistry of the American pitcher-plants, by Joseph S. Hepburn, Frank M. Jones, and 



Elizabeth Q. St. John. Transactions of the Wagner Free Institute of Science, vol. 11, 192.7. 



Four articles relating to pitcherplants have previously been published by the writer: 



Acidity relations of the Sarracenias. Journal of the Washington Academy of Sciences, vol. 19, 

 p. 379, 192.9. (The species ranges given in that paper are somewhat modified in the present 

 one in accordance with data subsequently obtained.) 



The geographic relations of Sarracenia purpurea. The Appalachian relative of Sarracenia flava. 

 Bartonia, vol. 15, p. i, 1933. 



Exploring for plants in the Southeastern States. Scientific Monthly, vol. 38, p. 80, 1934. 



As pointed out in the paper by the writer on Sarracenia purpurea, some recently pub- 

 lished maps of the distribution of the members of the Sarraceniaceae (Die Pflanzenareale, 

 vol. 3, pt. I, 193 1 ) are not satisfactory, having been constructed from incomplete data for 

 most of the species. A new set of maps is accordingly presented herewith, based on a thor- 

 ough review of the literature, a cataloging of numerous herbarium records, and extensive 

 field observations. 



The base map shows, in addition to State boundaries, two geologic lines of plant-geo- 

 graphic significance. The more northern of these represents the limit reached by the last, or 

 Wisconsin, ice sheet, as mapped by Antevs (Bulletin of the Geological Society of America, 

 vol. 40, p. 63 1, 192-9). The southern line is the fall line, taken from the map of Physiographic 

 Divisions of the United States, published by Fenneman (Annals of the Association of American 

 Geographers, vol. 6, p. 19, 19 17). Most of the territory enclosed between these lines has been 

 continuously available for occupancy by plants since Cretaceous time, when the development 

 of our modern flora began. 



On the individual maps, areas where the species is frequent in favorable habitats are 

 dotted. When the boundaries have been fairly definitely determined, they are marked by 

 solid lines, and when only approximately known, by dash lines. Presumable migration routes 

 are indicated by arrows. 



Before the individual species are discussed, the geologic relations of the group as a whole 

 require brief consideration. Physiographic studies indicate that prior to and during the Creta- 

 ceous much of eastern North America was reduced to a peneplain. The sea then extended 

 up to what is now the fall line, and for some distance northward and westward from this 

 boundary the conditions for plant growth were similar to those of our present-day Coastal 

 Plain. There were vast level areas covered by alluvial sands and clays, traversed by sluggish, 



2. 



