Background/Question/Methods The carnivorous wetland herb, Sarracenia purpurea (the Northern Pitcher Plant) is native to eastern and midwestern North America. This species is abundant within its habitat but suitable habitat is increasingly scarce, raising interest in S. purpurea restoration and conservation. Funding is usually limited for restoration work, making prioritization of individual populations, subspecies, or species important. Two subspecies are historically defined primarily on morphology: S. purpurea purpurea is the subspecies distributed north of New Jersey and S. purpurea venosa the subspecies south of New Jersey. S. purpurea is also found in three distinct habitat types: acidic sphagnum peatlands, acidic sandy savannahs, and alkaline marl wetlands. S. purpurea leaves have shown morphological plasticity in response to environmental variability, bringing into question the validity of subspecies definitions based on morphology alone. This study examined morphological and genetic variation throughout the S. purpurea natural distribution, encompassing both the historical subspecies and three unique habitat types to test the validity of historical subspecies definitions.

Results/Conclusions Genetic analysis indicated the significance of considering a new grouping of S. purpurea populations into Midwest, N. East Coast and S. East Coast populations (AMOVA = 52%, p = 0.0078) based on genetic differentiation. Morphological variation in leaf shape measurements supported this division as well as indicating plasticity associated with environmental variables. This study conservatively suggests that new, geographical area conservation units may be more important for preserving S. purpurea genetic variation and morphological plasticity than historical subspecies definitions.