Viburnum bracteatum (Adoxaceae) Expanded to Include Viburnum ozarkense

ABSTRACT Viburnum ozarkense was recently resurrected as a distinct species after having been synonymized with the related and partially sympatric Viburnum molle for much of the latter half of the 20th century. Presently, V. ozarkense is considered to be endemic to the Interior Highlands physiographic region of western Arkansas, southern Missouri, and eastern Oklahoma. However, this research suggests that although V. ozarkense is morphologically distinct from V. molle, it cannot be distinguished from V. bracteatum, a species found more than 500 km away in southeastern Tennessee, northeastern Alabama, and northwestern Georgia. Based on morphological and phytogeographical evidence, V. ozarkense is here considered to be conspecific with V. bracteatum. An overview of the expanded taxonomic concept, distribution, ecology and rarity of V. bracteatum is provided.