Abstract
We discovered an unknown Dendrobium taxon from the northwestern region of Tengchong City, Yunnan Province, China, which exhibits characteristics intermediate between Dendrobium wardianum and Dendrobium falconeri. Morphological analysis indicated that this taxon displays a mosaic of morphological characters derived from sympatric D. wardianum and D. falconeri with overlapping flowering periods: its vegetative organs (cylindrical stem, inconspicuous nodes, narrowly oblong leaves) are consistent with D. wardianum; the floral sepal shape (ovate-lanceolate) and wavy lip margins are similar to D. falconeri; while the two dark purple patches at the base of the lip are inherited from D. wardianum. It is named Dendrobium × falconerwardianum. Molecular biological analysis based on nuclear markers (internal transcribed spacer, ITS) and plastid markers (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit, rbcL) also indicated that D. × falconerwardianum is a natural hybrid of D. wardianum and D. falconeri. Based on combined morphological and molecular analyses, it is concluded that this taxon represents a natural hybrid of D. wardianum and D. falconeri. This discovery not only enriches the diversity of the genus Dendrobium, but also provides new insights into the evolutionary dynamics and gene flow barriers within the genus.