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The Asteraceae is the largest family of plants in North America and is widely used as medicine by Indigenous peoples. This study investigated the medicinal ethnobotany of North American Asteraceae to identify taxa that appear preferentially selected or avoided for general and specific medicinal uses. Asteraceae-specific ethnobotanical reports recorded in the Native American Ethnobotany database were compiled and, using residual and binomial analyses, 14 tribes were compared and ranked as either over- or under-selected for medicine, food, or technology, and for different categories of medicinal applications. Statistical analysis supported the hypothesis that the selection of species for ethnobotanical purposes is non-random and does not depend on the size of the flora. The Anthemideae tribe was identified as over-selected for all types of applications, including most therapeutic categories, most significantly as pulmonary and orthopedic aids. Subsequent analysis revealed that the over-representation of this tribe was attributed mainly to Achillea millefolium L. and Artemisia spp. The significance of Anthemideae, particularly of Achillea and Artemisia species as highly selected medicinal taxa, emphasizes their cultural importance to Indigenous North Americans. Residual and binomial statistics generally provided parallel results, but supplementary statistical methods, further in-depth investigation of other use categories, and inclusion of plant distribution data may provide greater insight into traditional uses of Asteraceae in North America.

Plants of the genus Echinacea have received extensive research attention, yet relatively little is known about the fruit (cypselae) of this economically important genus. The goal of this study was to investigate and compare the cypselae of four species of Echinacea: E. purpurea (L.) Moench, E. angustifolia DC., E. pallida (Nutt.) Nutt., and E. paradoxa (Norton) Britton, with respect to chemistry and germination. The phytochemical content of various fruit fractions was analyzed by high performance liquid chromatography with diode-array detection, identifying several alkylamides and caffeic-acid derivatives of medicinal value in all of the tissues. Alkylamides were most concentrated in the perianth and glands, whereas phenolics were generally enriched within the seed. Germination studies of intact cypselae and de-coated seeds demonstrate that the influence of cypsela coatings on germination depends on the growth environment. Removal of the perianth and pericarp resulted in decreased germination in soil, but significantly improved the germination of seeds of all species when sown in a sterile agar medium. In contrast, a higher percentage of intact cypselae of E. purpurea, E. angustifolia, and E. pallida germinated in soil than in sterile agar. These results suggest an ecophysiological role for phytochemicals in seed germination and will inform the cultivation and breeding of less common Echinacea species as well as the development of new products from currently unused plant material.