Field observations of vegetational patterning suggested that R. crispus, a common species of field margins and wastelands, might be allelopathic. Tests on seedling growth showed several dilutions of aqueous fresh-leaf R. crispus extracts significantly inhibited Amaranthus retroflexus, grain sorghum and field corn. Chromatography of these extracts established the presence of three phenolics which inhibited grain sorghum and radish in germination bioassays. These phytotoxins were characterized in several solvent systems, but attempts at identification were not successful. Field sampling showed a reduced plant biomass in quadrats near R. crispus and several species were found better established away from R. crispus. These data suggest that allelopathy may be important in the early invasion of waste areas by R. crispus.
The American Midland Naturalist has been published for 90 years by the University of Notre Dame. The connotations of Midland and Naturalist have broadened and its geographic coverage now includes North America with occasional articles from other continents. The old image of naturalist has changed and the journal publishes what Charles Elton aptly termed "scientific natural history" including field and experimental biology. Its significance and breadth of coverage are evident in that the American Midland Naturalist is among the most frequently cited journals in publications on ecology, mammalogy, herpetology, ornithology, ichthyology, parasitology, aquatic and invertebrate biology and other biological disciplines.
Simultaneously an international center for Catholic thought, a teaching-focused liberal arts college, and a dynamic hub for research and scholarship, the College of Arts and Letters at the University of Notre Dame provides its students with an education that fuels their passion for learning while preparing them to make a difference in the world. The largest and oldest college in the university, Arts and Letters houses the divisions of the arts, humanities, and social sciences. It encompasses 21 departments, more than 40 undergraduate and graduate degree programs, and a variety of interdisciplinary centers. Approximately 2,500 undergraduates and 750 graduate students pursue degrees through Arts and Letters programs; students from throughout Notre Dame enroll in thought-provoking Arts and Letters courses.
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The American Midland Naturalist
© 1973 The University of Notre Dame