Phenology of Limestone adder’s-tongue (Ophioglossum engelmannii ):  Ophioglossaceae in Collin County, Texas

 

Limestone adder’s-tongue is the only native fern species reported to Collin County and is only known from a single population.   Because of it’s small size and limited distribution, the status of this fern is classified as “not ranked/under review” at both the state and national level.  This relatively small and unusual fern produces a leaf that consists of two parts -  a vegetative portion that appears first and a reproductive, spore-bearing structure that appears later.  The above ground portions typically die after a few weeks.  The first specimen documenting its presence was collected in March 2003 from a population consisting of approximately 400 plants in an area 1 meter wide and 5 meters long.  Population density, dates and numbers of plants at various stages of development are being monitored.