A new species and a replacement name in Cynanchum (Apocynaceae, Asclepiadeae) from China.

Cynanchumpingtaoi S.Jin Zeng, G.D.Tang & Miao Liao, sp. nov. (Apocynaceae) from Yunnan Province, China, is described and illustrated based on morphological and molecular evidence. Its deeply cordate to reniform leaves and campanulate, large flowers show that it is a member of former Raphistemma Wall., which has been included in Cynanchum L.. It is different from all former Raphistemma species by the broadly ovate corolla lobes, purple-red corolla and connivent corona tip slightly exceeding the corolla throat. Meanwhile, Cynanchumlonghushanense G.D.Tang & Miao Liao, nom. nov. is proposed as replacement name for Raphistemmabrevipedunculatum Y.Wan, which was considered a synonym of Cynanchumhooperianum (Blume) Liede & Khanum but is here reinstated as a distinct species because of significant morphological differences.

Fordiophytontereticaule (Melastomataceae), a new species from China.

A new species, Fordiophytontereticaule, from China, is described and illustrated here based on morphological and molecular evidence. It is morphologically similar to F.faberi in having erect stems, slightly oblique and membranous leaf blades, broadly ovate to suborbicular bracts, and oblong petals, but differs by the terete stems, densely puberulous petioles, and elliptic leaf blades. Our phylogenetic analyses based on plastid genome and nrITS data indicate that this new species is clustered with four Fordiophyton species of Yunnan but placed far apart from F.faberi. An updated key to the genus is also provided.

Tigridiopalma exalata, a new and endangered species of Melastomataceae from China.

A new species of the genus Tigridiopalma, formerly considered monotypic, is here described as T. exalata and illustrated based on molecular and morphological evidence. It is morphologically similar to T. magnifica in having a short stem, huge basal leaves, scorpioid cymes, and 5-merous flowers, but differs in having ribbed and pale yellow puberulent petioles, purple petals with a small white apical patch, connectives of longer stamens with a distinct dorsal short spur at their base, and wingless capsules. Due to the restricted distribution, small populations and horticultural potential of this new species, it should be categorized as an Endangered species (EN).

Complete plastome sequence of Hoya carnosa (L. f.) R. Br. (Apocynaceae).

Hoya is a remarkable genus with high horticultural ornamental value. In this study, we report and characterize the complete plastid genome sequence of Hoya carnosa. The complete chloroplast genome was 176,340 bp in length, which includes a pair of inverted repeat regions (IRs) of 41,381 bp separated by a large single copy region (LSC) 91,281 bp and a small single copy region (SSC) 2,297 bp. Interestingly, IRs expanded into SSC, with the result that most of the genes in SSC were duplicated. This chloroplast genome contained 110 genes, including 76 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. The complete plastome sequence of H. carnosa will provide some useful information for future phylogenetic study of Hoya and its horticultural application.

Author Correction: The Apostasia genome and the evolution of orchids.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The complete chloroplast genome sequence of Blastus pauciflorus (Melastomataceae).

Blastus pauciflorus, a shrub endemic to Hong Kong and Guangdong, south China, growing on low-altitude hillsides, under the forest. The species is controversial in classification. Herein, we report the complete chloroplast genome sequence assembled from Illumina pair-end sequencing data, with aims to resolve its relationship with the related species. The complete chloroplast genome was 155,983 bp in length, includes two inverted repeat regions (IRs) of 26,716 bp each, which were separated by a large single copy region (LSC) 86,101 bp and a small single copy region (SSC) 16,450 bp. The chloroplast genome contained 129 genes, including 82 protein-coding genes, 2 pseudogenes, 37 tRNA genes and 8 rRNA genes. The overall GC content in the chloroplast genome of B. pauciflorus was 37.0%. Phylogenetic analysis showed that B. pauciflorus is closed to B. cochinchinensis.

The Apostasia genome and the evolution of orchids.

Constituting approximately 10% of flowering plant species, orchids (Orchidaceae) display unique flower morphologies, possess an extraordinary diversity in lifestyle, and have successfully colonized almost every habitat on Earth. Here we report the draft genome sequence of Apostasia shenzhenica, a representative of one of two genera that form a sister lineage to the rest of the Orchidaceae, providing a reference for inferring the genome content and structure of the most recent common ancestor of all extant orchids and improving our understanding of their origins and evolution. In addition, we present transcriptome data for representatives of Vanilloideae, Cypripedioideae and Orchidoideae, and novel third-generation genome data for two species of Epidendroideae, covering all five orchid subfamilies. A. shenzhenica shows clear evidence of a whole-genome duplication, which is shared by all orchids and occurred shortly before their divergence. Comparisons between A. shenzhenica and other orchids and angiosperms also permitted the reconstruction of an ancestral orchid gene toolkit. We identify new gene families, gene family expansions and contractions, and changes within MADS-box gene classes, which control a diverse suite of developmental processes, during orchid evolution. This study sheds new light on the genetic mechanisms underpinning key orchid innovations, including the development of the labellum and gynostemium, pollinia, and seeds without endosperm, as well as the evolution of epiphytism; reveals relationships between the Orchidaceae subfamilies; and helps clarify the evolutionary history of orchids within the angiosperms.