Abstract Detail

Systematics

Lyon, Stephanie [1], Ress, Trent [2], Boy, Levi [2].

Phylogeny and seed morphology in Platanthera orchids.

The orchid genus Platanthera is the largest group of orchids in temperate North America and is also widely distributed through Eurasia. To date, there is published phylogeny for the genus that includes adequate sampling of species from both North America and Eurasia. Using existing published sequence data from a number of different sources, combined with newly generated chloroplast sequences for several key North American taxa including P. orbiculata, P. clavellata, and P. flava, we reexamine phylogenetic relationships within Platanthera. The resulting molecular phylogeny is used to 1) test recently proposed subgeneric classifications based on floral morphology, 2) examine biogeographical patterns within the genus including the number of transitions between North America and Eurasia, and 3) provide a framework for studying the evolution of seed micromorphology within the genus, particularly the size and shape of seed, the number, size, and shape of cells in the seed coat, and features of their periclinal and anticlinal walls. Seed micromorphology has been suggested as an important source of taxonomic characters for subdividing the genus, but has been examined in only a small number of species. Samples of eight additional species from historical seed collections at WIS and UWSP herbaria, were processed and imaged using via scanning electron microscopy (SEM). Implications for Platanthera systematics are discussed.

1 - University Of Wisconsin-Stevens Point, Biology, 2101 Fourth Ave., Stevens Point, WI, 54481, United States
2 - University of Wisconsin-Stevens Point, Biology

Keywords:
Platanthera
seed micromorphology
phylogeny
Scanning Electron Microscopy
Orchidaceae.

Presentation Type: Poster
Session: P3, Systematics Posters
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 5:00 PM(EDT)
Number: P3SY012
Abstract ID:1142
Candidate for Awards:None