Demography and Phenology of Winter Grape Fern (Botrychium lunarioides): Ophioglossaceae in Choctaw County, Oklahoma

 

The winter grape fern is an unusual plant that begins growing in the fall, grows throughout the winter and dies in the spring.  Because of it’s small size and limited distribution, relatively little is known about it’s life cycle and natural history.  A fern expert has been quoted as stating that it’s so rare that fewer than 1 in 1,000 botanists has even seen it in it’s natural state.   In Oklahoma, it is classified as “critically imperiled”.  It was first reported in Oklahoma from a cemetery in Choctaw county in 1972 by a Botany Professor from Louisiana. 

The purpose of this study is to monitor the individual ferns and document the life cycle events (population size, population density, date of peak population size, emergence date, growth, reproduction and death) on an annual basis.   

The study site is located at a cemetery in Choctaw county, Oklahoma and  consists of 20 study plots arranged in a cross type pattern approximately 10 yards long and 10 yards wide.  Each study plot measures one square meter (approx. 1 yard square).

The search for plants in the study site begins in September.  As plants are found, each plant location is recorded and a numbered aluminum tag is inserted in the ground near the plant.  Data recorded for each plant include the developmental stage and size of the plant.  The sites are revisited monthly through May.  Growth and developmental stage are recorded for all new and previously marked plants each month.