First Reports of Ceratophyllum echinatum A. Gray from Indiana with Notes on the Distribution, Ecology and Phytosociology of the Species

During an extensive floristic survey to catalogue the aquatic macrophyte distribution of the Valparaiso Chain of Lakes Watershed, the first record of Ceratophyllum echinatum A. Gray in Indiana was made at Deep Lake in Porter County. The species has subsequently been found in fourteen additional lakes, predominantly throughout Northern Indiana. Although these are the first records of this species in Indiana, the historical scarcity of comprehensive aquatic plant surveys in the state and our knowledge of the geographical range of this species throughout the Midwest, leads us to believe that this species has been in Indiana for an extended period. The close similarity in vegetative morphology among Ceratophyllum echinatum, Ceratophyllum demersum L. and other aquatic plant species with finely dissected leaves, such as Myriophyllum species, has also likely been a contributing factor leading to an under representation of this species in floristic surveys. Voucher specimens of Ceratophyllum echinatum are deposited in the Aquatic Plant Herbarium of Purdue University North Central.