Two new species of Sabulina (Caryophyllaceae) from Washington State, U.S.A.

Ben S Legler,Markus S Dillenberger

doi:10.3897/phytokeys.81.13106

Abstract

Sabulina basaltica and Sabulina sororia (Caryophyllaceae) are described as new species endemic to Washington State, U.S.A. Sabulina basaltica is restricted to high-elevation, basalt rocks in the northeastern Olympic Mountains, and Sabulina sororia to high-elevation, dunite rocks of the Twin Sisters Range in the North Cascade Mountains. Both were previously confused with Sabulina rossii (formerly called Arenaria rossii or Minuartia rossii). Their recognition as distinct species is supported by morphological and molecular characters and disjunct geographic distributions. Both are illustrated, mapped and compared to related species. We also present a molecular phylogeny of Sabulina based on nuclear ITS and plastid trnQ-rps16 DNA with increased sampling of North American taxa. The phylogeny resolves a single clade containing all glabrous, perennial, North American Sabulina taxa including Sabulina rossii and both of the new species.

Highlights

While preparing a new Flora of the Pacific Northwest (Giblin et al, in press) the status of specimens from the North Cascade and Olympic Mountains in Washington State formerly called Arenaria rossii R
Morphological comparisons indicate the plants from the Olympic Mountains (Sabulina basaltica in Table 1 and the key) differ from plants from the Twin Sisters Range (S. sororia) in leaf veination, sepal shape, sepal length, sepal length:width ratio, and capsule length relative to sepals, with minimal or no overlap between the two species in these characters (Table 1)
Sabulina basaltica and S. sororia can be reliably distinguished from each other morphologically (Table 1, and see key), with the differences comparable to those used to distinguish among other members of the S. rossii species complex, suggesting they are appropriately recognized at the same taxonomic rank of species

Summary

Introduction

While preparing a new Flora of the Pacific Northwest (Giblin et al, in press) the status of specimens from the North Cascade and Olympic Mountains in Washington State formerly called Arenaria rossii R. Herbarium specimens of the two new species were first collected in 1911 from the Olympic Mountains and in 1939 from the Twin Sisters Range in the North Cascade Mountains, with the most recent collections prior to this study made in 1984 from the Olympic Mountains and in 1968 from the Twin Sisters Range. These specimens, 17 in total, are held by three local herbaria (OLYM, WTU and WWB; acronyms according to Thiers continuously updated); no duplicates were located through searches of digitized specimens at other herbaria

Methods

Results

Conclusion