WeDigBio Talk (Arkansas rare plants)

WeDigBio is just a week away! We are getting ready for the event and want to announce the first in a series of talks that everyone is invited to.

Calcareous cliff at Campbell Hollow, photo by Theo Witsell.

The first is will be presented by Theo Witsell, Arkansas Natural Heritage Commission Chief of Research and Inventory / Ecologist / ANHC Herbarium curator. It is titled “The Significance of Cliff and Talus Communities as Habitats for Rare Plant Species in the Interior Highlands of Arkansas” and will be held on Saturday, October 16 from 7-8:00 pm central time (UTC -5). A description of the talk is below.

To register in advance for this meeting:
https://ufl.zoom.us/meeting/register/tJMrdOyvqD4tGdMKXu7SxBT-U_29NGPYz7rv

Left: Arkansas Springbeauty (Claytonia arkansana) grows in rock crevices of sandstone cliffs in three counties in the Interior Highlands of Arkansas, photo by Theo Witsell. Right: Ouachita Twistflower (Streptanthus squamiformis), a Ouachita Mountains endemic, grows in sandstone and shale glades in three counties of southwestern Arkansas and one county in southeastern Oklahoma, photo by Brent Baker.

After registering, you will receive a confirmation email containing information about how to join.

The Plants of Arkansas project has hosted many expeditions with plants collected from the Interior Highlands for almost three years. In this presentation, you can learn about the cliff and talus communities in Arkansas, which are known to support many state and globally significant plant species of conservation concern, yet no systematic analysis of these habitats or the rare species they support has been conducted.  Cliff and talus habitats in the Interior Highlands (the Ozark Plateaus, Boston Mountains, Arkansas Valley, and Ouachita Mountains) are typically associated with medium- to large-sized streams, but also occur in association with faults and other geologic contacts.  These habitats have been heavily impacted by inundation following the construction of several large reservoirs on many of the larger stream systems, most notably the White River system in the Ozark Plateau, and the Ouachita River system in the Ouachita Mountains. However, remaining habitat still supports rare species.  An overview of the flora of conservation concern in these communities will be presented in terms of ecoregion, geologic substrate, moisture gradient (wet to xeric), and physical site characteristics such as microhabitat, slope, and aspect. Several of the plants of conservation concern in these habitats are endemic to the Interior Highlands and others represent significant range disjunctions. Biogeographical patterns of these rare species present will also be discussed. Important endemic plant taxa associated with cliffs and related outcrops in the region include Amorpha ouachitensis, Claytonia arkansana, Dirca decipiens, Elymus churchii, Elymus glaucus ssp. mackenzii, Heuchera villosa var. arkansana, Houstonia ouachitana, Liatris compacta, Quercus acerifolia, Solidago ouachitensis, Streptanthus maculatus ssp. obtusifolius, Streptanthus squamiformis, Tradescantia ozarkana,and Valerianella ozarkana. Appropriate management of these sites will be discussed.