Holoparasitic Orobanchaceae in Georgia (Caucasus): taxonomic revision, diversity, distribution, habitats and host range

Abstract

This study represents the first comprehensive monograph of the tribe Orobancheae (Orobanchaceae) in the four holoparasitic genera, Cistanche, Phelypaea, Phelipanche, and Orobanche, in Georgia. This country, as a part of the Caucasus, is one of the most important biodiversity centres in the world and includes poorly understood holoparasitic plants. Species delimitations are re-evaluated on the basis of critical observations on seven years of field work and examination of ca. 1000 herbarium sheets from 50 herbaria. Our work has resulted in the recognition of 33 species, among which 13 are endemic to the Caucasus. We present information on their distribution, localities, habitat, phenology, host range, images from the field, nomenclatural acts (taxonomic clarifications, proposals for new synonymisations, new combinations, lectotypifications), as well as a key for identification and preliminary geospatial conservation assessments for all species based on IUCN criteria. Lectotypes are designated for Cistanche fissa, C. sintenisii, Orobanche salsa var. ambigua f. fissa, O. salsa var. ambigua f. longiloba, O. coelestis f. confinis, O. ramosa var. penicillata, O. coerulescens, O. buhsei, O. glabrata, O. minor, O. libanotidis, O. flava; neotype for O. owerinii; nomenclatural novelties, new combinations and/or a name at new rank: O. doriae, Orobanche subg. Gamosepalae, Orobanche sect. Arcuatae.