Effect of Self- and Cross-pollination Treatments and Microhabitat on Seed Germination of Prosthechea cochleata and Encyclia tampensis (Orchidaceae) in Southern Florida

Haleigh A. Ray^1,*, Michael E. Kane², and Jennifer L. Gillett-Kaufman¹

¹1881 Natural Area Drive, Steinmetz Hall, Entomology and Nematology Department, University of Florida, Gainesville, FL 32611.²Environmental Horticulture Department, University of Florida, PO Box 110675, Gainesville, FL 32611. *Corresponding author.

Southeastern Naturalist, Volume 19, Issue 3 (2020): 601–611

Abstract
In south Florida, over 100 species of native orchids occur, many of which need conservation efforts. Two of these species, Prosthechea cochleata (Clamshell Orchid) and Encyclia tampensis (Tampa Butterfly Orchid), are listed on Florida’s Regulated Plant Index as endangered and commercially exploited, respectively. In this study, we covered flowers with fine-mesh exclusion bags and counting the number of resulting seed capsules to examine the capability of Clamshell Orchids to spontaneously self-pollinate in the field. We also examined capsule formation on flowers of this species that we cross-pollinated by hand in a greenhouse at the University of Florida. Additionally, we collected Tampa Butterfly Orchid seed capsules from various microhabitats at the Florida Panther National Wildlife Refuge. The seeds from all of these seed capsules were surface-sterilized and placed on a nutrient medium made for orchid seeds. We examined the percentage of successful germination of seeds from those seed capsules, either uncovered, bagged (and presumably self-pollinating), or hand cross-pollinated for the Clamshell Orchids, and from different microhabitats in south Florida for the Tampa Butterfly Orchid. We found that Clamshell Orchids are likely to be self-pollinating in the field, with over 90% germination of seed from covered flowers. Additionally, there was no significant difference between germination from uncovered, bagged, or hand cross-pollinated Clamshell Orchid flowers, or between areas of the FPNWR where capsules were collected. The Tampa Butterfly Orchid capsules collected also showed no significant difference in germination between locations collected. The information from this study will be useful in efforts toward germination and out-planting of orchid species.

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