Abstract Detail

Systematics Section/ASPT

Gillespie, Emily [1].

Evolution of the circumboreal genus Cassiope (Ericaceae) with emphasis on leaf form and putative hybrid species.

The genus Cassiope (Ericaceae) includes approximately 17 species of small evergreen shrubs that inhabit alpine and subalpine areas at high latitude and/or elevation in the northern hemisphere. Superficially, members of the genus are morphologically similar. Flowers in this group tend to be small, solitary and bell-shaped, and are most commonly light pink to white. All Cassiope species have very small leaves and most are decussate and appressed to the stem. In detail, however, leaves are quite variable among species. Four basic leaf forms occur; most have an ‘ericoid’ leaf form, where the abaxial surface has a deep groove. A small number of species have more or less planar leaves or slightly thickened or abaxially concave leaves. One species has a leaf that essentially forms a tube at the base. Initial attempts to generate a phylogeny of Cassiope included more than 75% of the named species, but the most unusual leaf type, the tubular leaf, was not represented. These analyses revealed that at least three species’ may have hybrid origins. The current study includes the tubular-leaf species and doubles the original molecular data set. Here, we discuss the improvement of the phylogeny of Cassiope, evolution of leaf form with emphasis on the placement of the tubular leaf type, and further evaluation of apparent reticulate evolution within the genus.

Broader Impacts:

1 - Marshall University, 1700 3rd Avenue, Huntington, WV, 25755, USA

Keywords:
molecular phylogeny
reticulate evolution
hybridization
circumboreal
leaf evolution.

Presentation Type: Oral Paper:Papers for Sections
Session: 4
Location: Magnolia/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 10:45 AM
Number: 4009
Abstract ID:851
Candidate for Awards:None