Taxonomic implications of floral morphology in the subfamily Asclepiadoideae (Apocynaceae s.l.) in Korea

Abstract

We examined the floral morphology of 15 taxa of five genera (Cynanchum, Marsdenia, Metaplexis, Tylophora, and Vincetoxicum) in Korean Asclepiadoideae using a stereoscopic and scanning electronic microscope to clarify and describe the floral characteristics. In this study, the corolla and corona types, the types of corona lobes, appendages on the corona lobes, and the apex shape of the style head are considered as diagnostic characteristics at the generic level. The genus Vincetoxicum, which is treated as a synonym of the genus Cynanchum in Korea, is distinguished from Cynanchum by the interstaminal part on the corona, fleshy and mainly triangular or ellipsoid corona lobes, and various corolla colors. In Cynanchum, various corona types have been observed, while Vincetoxicum have similar corona types among the taxa. In addition, the main floral characteristics at the species level were as follows: flowering time, inflorescence, corolla color, trichomes on the corolla surfaces, apex shape of the corona lobe, and trichomes on the ovary. This study presents the taxonomic importance of floral morphology by providing descriptions and diagnostic characteristics among the genera and species investigated.

The complete plastome of Cynanchum rostellatum (Apocynaceae), an indigenous plant in Korea

“…2014 ). This species can be distinguished from other species by having an elongated stigma and purple furry petals in flower morphology (Nam and Chung 2018 ). However, when flowers fall, C. rostellatum is frequently misidentified as C. wilfordii , one of the most famous medicinal plants in Korea, especially during the harvesting season (Kim et al.…”

Genome structure and diversity among Cynanchum wilfordii accessions

“…Notably, Cw has a special stamen shape, with an anther sac and wing [ 25 ], and the stigma head surrounded by a paracorolla. This complex and unusual floral structure is a special feature of the Apocynaceae (Fig.…”

New distribution records of two rare species of <i>Cynanchum</i> (Apocynaceae) in South Korea: <i>Cynanchum thesioides</i> (Freyn) K. Schum. and <i>Cynanchum chinense</i> R. Br.

“…Habitat and ecology: In Korea, the species grows in open areas of seashore, swamp edges, and roadsides, along with Note: Cynachum chinense mainly occurs in thickets, roadsides, seashores, and riverbanks in China, Mongolia, and Korea (Li et al, 1995). It is clearly distinguished from other species within the genus Cynanchum by its triangular leaves with cordate bases and a tubular corona with long and slender appendages (Nam and Chung, 2018) (Fig. 4).…”

“…The genus is morphologically distinguished from Vincetoxicum Wolf. by twining stems, white latex, and mostly heart-shaped leaves; it also exhibits high diversity in floral structures, especially in corona shapes (Khanum et al, 2016;Nam and Chung, 2018).…”

“…Hemsl. (Khanum et al, 2016;Nam and Chung, 2018). C. purpureum and C. thesioides have been reported in North Korea, C. chinense is restricted to South and North Korea, and C. wilfordii is distributed from the seashore to mountain slopes in the Korean peninsula (Lee, 1996;Im, 1999;Chang et al, 2014).…”