North American Prairie Conference


Date of this Version



Published in Prairie Pioneers: Ecology, History and Culture: Proceedings of the Eleventh North American Prairie Conference, August 7-11, 1988, Lincoln, Nebraska (Lincoln, NE 1989).


Flowering and fruiting patterns for 74 species of native angiospenns were studied on South Padre Island, Texas, from May 1984 to May 1986. Four patterns were recognized: 1) a continuous cycle of flowering and fruiting; 2) a cycle limited to spring through autumn; 3) a two season regime, either spring-summer or summer-fall; and 4) a cycle completed in one season or less (spring or fall). Marked year-to-year variation occurred in flowering and fruiting responses within individual species. Only one-fifth ofthe species exhibited the same monthly patterns in successive years. Number of species in flower or fruit was significantly correlated with mean monthly temperature and photoperiod, but showed no correlation with total monthly precipitation or precipitation with a one month time lag. Insect pollinated species had longer flowering/fruiting periods than wind pollinated species. Flowering and fruiting responses were compared among species common to other Gulf of Mexico islands and with species in common with temperate grasslands.