Conservation and re-establishment of Florida panhandle goldenasters (Chrysopsis): I. Reproduction characteristics and germination requirements

Abstract

Goldenasters (Chrysopsis (Nutt.) Elliott [Asteraceae]) are southeastern US native sunflowers that are important components of imperiled plant communities. However, information is limited regarding their conservation and restoration. We investigated reproduction characteristics and germination requirements for 3 Chrysopsis taxa: 2 forms of Godfrey’s goldenaster (Chrysopsis godfreyi Semple f. godfreyi and Chrysopsis godfreyi f. viridis Semple) and Cruise’s goldenaster (Chrysopsis gossypina ssp. cruiseana (Dress) Semple). The total number of inflorescences per plant, heads per inflorescence, heads per plant, and seeds per head were counted for plants growing in coastal back dunes in the Florida panhandle. The number of seeds per plant was estimated. Initial viability and germination tests were conducted by a seed testing laboratory. Effects of photoperiod (0 or 12 h) and temperature on germination were also evaluated. Reproductive characteristics did not differ among the 3 taxa, but there were differences in seed viability and germination. Seeds of C. godfreyi f. viridis and C. gossypina ssp. cruiseana had high (>70%) viability compared to C. godfreyi f. godfreyi (<50%). We observed a significant interaction between temperature and light for all 3 taxa. The highest germination percentages (50–56%) for C. godfreyi f. godfreyi were recorded in winter and early spring/late fall temperatures with light. Similarly, the highest germination percentages (58–71%) for C. godfreyi f. viridis and C. gossypina ssp. cruiseana were recorded in winter, early spring/late fall, and early fall/late spring temperatures in light. We recommend collecting seeds in the late fall to winter and immediately sowing with light exposure.