REPRODUCTIVE PHYSIOLOGY IN THE SEAGRASS, SYRINGODIUM FILIFORME, FROM THE GULF OF MEXICO AND THE CARIBBEAN

Abstract

Reproductive physiology in Syringodium filiforme Kütz. is controlled primarily by temperature under day lengths ranging from 12 hr to continuous light. Texas plants can be induced to flower at temperatures ranging from 20 to 24 C, but southern Gulf of Mexico and Caribbean plants are most readily induced at 23–24 C. Texas plants proceed to anthesis at temperatures above 22 C, but St. Croix plants require higher temperatures, above 25 C, for emergence of flowers from the bracts. Flowers induced under continuous light proceed to anthesis under day lengths shortened to 11 hr, but further floral induction is inhibited even under inductive temperatures. In natural seagrass beds, flowering occurs primarily under lengthening day lengths and warming temperatures that follow winter minima, but inflorescences may occur at other times of the year if temperatures permit.