Ortiz , Vivian Negron .
Reproductive ecology and conservation of a federally threatened Florida Panhandle species, Euphorbia telephioides Chapman (Euphorbiaceae).
Conservation of imperiled plant species requires an understanding of demography and reproductive biology, including breeding system and seed ecology. Euphorbia telephioides Chapman (telephus spurge) is a federally threatened herbaceous species primarily endemic to xeric and mesic pine flatwoods in three counties of northwest Florida. Plants are long-lived and individuals flower and fruit profusely, but seedling recruitment is rare or absent. As part of a long-term study to understand the conservation requirements of E. telephioides, I am investigating the growth and reproductive biology. In 2010 I established study sites throughout this species' range and monitored plant growth (number and length of stems) and reproduction (inflorescence length, gender, fruit and seed production) monthly. Plant emergence typically occurs in April, but was dramatically delayed for two months due to cold weather in 2010. Individuals in the Bay and Gulf County populations averaged 1.3 stems whereas Franklin County population plants averaged 2.3 stems. On average the Gulf County plants had larger stems than plants in the other populations, with more vegetative growth early in the season. Euphorbia telephioides is diclinous with separate staminate and pistillate flowers either on the same plant or on different plants. Populations averaged more reproductive plants than sterile (mean 74 % reproductive), with more females (mean 40 %) than males (mean 28 %); only one plant was found with both male and female flowers. Stem height differed significantly among the sexes, with females averaging 15.7 cm, males 13.9 cm, and steriles 11.7 cm (F = 3.9, p < 0.02). On average, fruit and seed production per female were higher for the Franklin population (means = 3.2 fruits, 9 seeds) than for the Bay (2.7, 8.2) and Gulf (2.3, 6.8) populations. Plants are permanently marked, enabling me to investigate growth and gender change relationships across years. Germination studies, which will be initiated in spring 2011, and conservation implications, will be discussed.
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1 - U.S. Fish and Wildlife Service, 1601 Balboa Avenue, Panama City, FL, 32405, USA
federally listed plants
Presentation Type: Poster:Posters for Topics
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM