Abstract Detail

Systematics Section/ASPT

Allphin, Loreen [1], BECK, JAMES [2], ALEXANDER, PATRICK [3], Li, Fay-Wei [4], Rushworth, Catherine [5], Bailey, C. Donovan [6], Al-Shehbaz, Ihsan [7], Windham, Michael D [8].

New insights into the taxonomy of the rare Park rockcress (Brassicaceae) from Dinosaur National Park.

Park rockcress is a rare perennial member of the mustard family known only from the immediate vicinity of Dinosaur National Park on the Colorado-Utah border. Originally described as Arabis vivariensis, this taxon was subsequently transferred to the genus Boechera, where it has been variously treated as a distinct species or as a synonym, variety, or subspecies of the Great Basin endemic B. fernaldiana. In the Flora of North America volume published in 2010, Park rockcress was considered a subspecies of B. fernaldiana, whereas another allopatric segregate from the southern Sierra Nevada (B. evadens) was treated as a distinct species. A recent phylogeny generated by Alexander et al. reveals that this treatment inaccurately portrays relationships within the B. fernaldiana species complex. This phylogeny shows 100% bootstrap support for a sister relationship between B. fernaldiana and B. evadens, while the position of Park rockcress, though unresolved with respect to the backbone, was clearly more distant. Analyses of a 15-locus microsatellite dataset with broad geographic sampling of B. fernaldiana and related taxa reveal additional details relevant to taxonomy of the group. The nomenclature of Park rockcress is significantly impacted by the discovery that the type collection of Arabis vivariensis includes two different taxa: 1) the isotype at RM is a sexual diploid representative of the majority of collections previously assigned to this taxon, and 2) the isotype at GH and the holotype at BRY represent a rare, apomictic diploid resulting from hybridization between this sexual diploid and B. thompsonii.  If the parents of 2) are considered distinct species (as they currently are), then B. vivariensis is appropriately recognized at species level. Under this scenario, however, the sexual diploid taxon comprising most specimens assigned to B. vivariensis would need a new name. One possible alternative involves expanding the circumscription of B. vivariensis to include the more recently described B. thompsonii. However, this would create an entirely different set of problems given the promiscuous nature of the latter. Here, we explore the interface among population genetics, nomenclature, and conservation as they apply to Boechera vivariensis.

1 - Brigham Young University, Plant and Wildlife Sciences, 275 Widtsoe Building, Provo, UT, 84602, USA
2 - Wichita State University, Biology, 1845 Fairmount, Box 26, Wichita, KS, 67260-0026, USA
3 - New Mexico State University, Biology Department, 248 Foster Hall, MSC 3AF, Las Cruces, NM, 88003, USA
4 - Duke University, Department of Biology, Durham, NC, 27708
5 - Duke University, PO Box 90338, Durham, NC, 27708, USA
6 - New Mexico State University, PO Box 30001 MSC 3AF, Las Cruces, NM, 88003, USA
7 - Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166-0299, USA
8 - Duke University, Department of Biology, Box 90338, Durham, NC, 27708, USA

Keywords:
Boechera
Brassicaceae
microsatellites
taxonomy
Conservation.

Presentation Type: Oral Paper:Papers for Sections
Session: 14
Location: Cottonwoods North/Boise Centre
Date: Monday, July 28th, 2014
Time: 1:30 PM
Number: 14001
Abstract ID:797
Candidate for Awards:None