Two New Species of Christisonia (Orobanchaceae) from Southeastern Yunnan, China

Abstract— Two new species of Christisonia (Orobanchaceae), Christisonia hekouensis Gui L.Zhang, J.D.Ya & W.B.Yu and Christisonia dentosa J.D.Ya, Gui L.Zhang & W.B.Yu, found during botanical surveys in Southeast Yunnan, China, are described and illustrated. The two new species are similar to C. kwangtungensis bearing rose-red flowers and conspicuously inflated corolla tubes, and phylogenetic analyses strongly support the three species as monophyletic. However, C. hekouensis can be distinguished from C. kwangtungensis and C. dentosa by having externally puberulent calyces and corollas, corolla lobes with serrulate margins, styles that are pink and glabrous or sparsely capitate-glandular pubescent above, and with anthers less than 2 mm below the stigma. Christisonia dentosa differs from C. kwangtungensis and C. hekouensis by having dentate corolla lobe margins, internally capitate-glandular pubescent corollas, styles distinctly capitate-glandular pubescent above, and more than six anthers which are up to 10 mm below the stigma.