DISTRIBUTION OF THE 

 NORTH AMERICAN PITCHERPLANTS 



BY EDGAR T. WHERRY 



Associate Professor of Botany, University of Pennsylvania 



The pitcherplant family [Sarraceniaceae] consists of three genera, Sarrace?ua, Chrysamphora, 

 and Heliamphora. Nine species of Sarracenia have been recognized thus far, one of them rang- 

 ing from the Gulf Coast far north into Canada, the others restricted to the southeastern 

 United States. The genus Chrysamphora^ also known as Darlingtonia^ is monotypic, its single 

 species occurring in northern California and southwestern Oregon. One species of Heliam- 

 phora was described in 1840 and for ninety years remained the only known representative 

 of the genus, but three more have now been found. These are limited to northern South 

 America, however, and will not be discussed in this article. 



KEY TO THE NORTH AMERICAN PITCHERPLANTS 



Pitcher hood bearing a fishtail-shaped appendage; scape bracted; petals bronzy yellow; style 

 radiate Chrysamphora calif ornica 



Pitcher hood not appendaged; scape naked; style normally expanded into an umbrella-shaped 

 structure Sarracenia 



Pitchers erect or essentially so. 



Pitcher orifice incompletely covered by hood. 



Margins of the large hood more or less reflex ed. 



Hood yellow-green, veined or suff"used with red. 

 Petal-color of a yellow type. 



Reflexing of hood margins slight; petal texture firm. 



Flat leaves abundant; petals greenish yellow . . S. oreophila 



Flat leaves sparse; petals creamy yellow S. sledgei 



Reflexing conspicuous; petals delicate, yellow S. flava 



Petal-color of a red type S. jonesii 



Hood white, green- and red-veined; petals red S. drummondii 



Margins of the small hood not reflexed; petals red S. rubra 



Pitcher orifice well covered by hood; petals yellow S. rninor 



Pitchers decumbent; petals red or exceptionally yellow. 



Orifice lateral, small; hood closed S. psittacina 



Orifice terminal, large; hood open. 



Pitcher outline short and broad S. purpurea venosa 



Pitcher outline long and narrow S. purpurea gibbosa 



Data as to the relationships and distribution of the species have been obtained mainly 

 from studies in the herbaria of the Academy of Natural Sciences of Philadelphia, Canadian 

 National Museum, Cornell University, Gray Herbarium, New York Botanical Garden, 



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