Bougainvillea is popular in ornamental horticulture for its colorful bracts and excellent adaptability, but the complex genetic relationship among this genus is fuzzy due to limited genomic data. To reveal more genomic resources of Bougainvillea, we sequenced and assembled the complete chloroplast (cp) genome sequences of Bougainvillea spectabilis ‘Splendens’. The cp genome size was 154,869 bp in length, containing 86 protein-coding genes, 38 tRNAs, and eight rRNAs. Cp genome comparison across 12 Bougainvillea species (B. spectabilis, B. glabra, B. peruviana, B. arborea, B. praecox, B. stipitata, B. campanulata, B. berberidifolia, B. infesta, B. modesta, B. spinosa, and B. pachyphylla) revealed five mutational hotspots. Phylogenetic analysis suggested that B. spectabilis published previously and B. glabra clustered into one subclade as two distinct groups, sister to the subclade of B. spectabilis ‘Splendens’. We considered the phylogeny relationships between B. spectabilis and B. glabra to be controversial. Based on two hypervariable regions and three common plastid regions, we developed five molecular markers for species identification in Bougainvillea and applied them to classify 53 ornamental Bougainvillea cultivars. This study provides a valuable genetic resource for Bougainvillea breeding and offers effective molecular markers to distinguish the representative ornamental species of Bougainvillea.

Hybridization is very common in flowering plants and it plays a significant role in plant evolution and adaptation.MelastomaL. (Melastomataceae) comprises about 80–90 species in tropical Asia and Oceania, among which 41 species occur in Borneo. Natural hybridization is frequently reported inMelastomain China, but so far there have been no confirmed cases of hybridization in Southeast Asia (including Borneo), where most species occur. Here, we identified a case of natural hybridization betweenMelastoma malabathricumL. andMelastoma beccarianumCogn. in Sarawak, Malaysia, by using sequence data of three nuclear genes and one chloroplast intergenic spacer.Melastoma malabathricumis the most widespread species of this genus, occurring in almost the whole range of this genus, whileM. beccarianumis a local species endemic to northern Borneo. Our results showed that natural hybridization and introgression occur betweenM. malabathricumandM. beccarianum, and the introgression was asymmetrical, mainly fromM. malabathricumtoM. beccarianum. As adaptive traits can be transferred by introgression, our study suggests that natural hybridization should be a significant mechanism for the evolution and adaptation ofMelastomain Southeast Asia. However, introgression from the common speciesM. malabathricumto the relatively rare speciesM. beccarianummay cause the decline ofM. beccarianum, incurring conservation concern. With a large number of species ofMelastomaand almost year‐around flowering in Southeast Asia, more cases of natural hybridization are expected to be found and identified in near future.

Reevesia thyrsoidea Lindl. is an important ornamental plant with horticultural, industrial, and timber usages. In this study, we reported a complete chloroplast genome of R. thyrsoidea, which was quadripartite and 161,786 bp in size, including two inverted repeats (25,466 bp for each) that separated one large single-copy (90,565 bp) and one small single-copy (20,289 bp) regions. The chloroplast genome contained 131 unique genes (86 protein-coding, 37 tRNA, and 8 rRNA), and 17 of them were double copies. Phylogenetic analysis using the chloroplast genome data indicated that R. thyrsoidea was sister to the species in the family Malvaceae.

Based on morphological comparison and literature consultation, a new species, Metapetrocosmea alba (Gesneriaceae), is confirmed from Bach Ma National Park, central Vietnam. This new species is similar to M. poilanei, but differs by its longer and white funnelform corolla and three staminodes. And it is easy to distinguish the new species from M. cycnostyla by its distinct stem, and the shape and size of leaf blade. A detailed morphological description and photographic illustration of the new species are provided along with ecological information and geographic distribution.

Understanding the genetic basis of species differences in flowering time and inflorescence architecture can shed light on speciation and molecular breeding. Melastoma shows rapid speciation, with about 100 species formed in the past few million years, and, meanwhile, possesses high ornamental values. Two largely sympatric and closely related species of this genus, M. candidum and M. normale, differ markedly in flowering time and flower number per inflorescence. Here, we constructed an F2 population between M. candidum and M. normale, and used extreme bulks for flowering time and flower number per inflorescence in this population to identify genomic regions underlying the two traits. We found high differentiation on nearly the whole chromosome 7 plus a few regions on other chromosomes between the two extreme bulks for flowering time. Large chromosomal inversions on chromosome 7 between the two species, which contain flowering-related genes, can explain recombinational suppression on the chromosome. We identified 1872 genes with one or more highly differentiated SNPs between the two bulks for flowering time, including CSTF77, FY, SPA3, CDF3, AGL8, AGL15, FHY1, COL9, CIB1, FKF1 and FAR1, known to be related to flowering. We also identified 680 genes with one or more highly differentiated SNPs between the two bulks for flower number per inflorescence, including PNF, FIL and LAS, knows to play important roles in inflorescence development. These large inversions on chromosome 7 prevent us from narrowing down the genomic region(s) associated with flowering time differences between the two species. Flower number per inflorescence in Melastoma appears to be controlled by multiple genes, without any gene of major effect. Our study indicates that large chromosomal inversions can hamper the identification of the genetic basis of important traits, and the inflorescence architecture of Melastoma species may have a complex genetic basis.

This study provides the first comparative community‐ecological and demographic assessment of the two extant species of Tigridiopalma (Melastomataceae), both of which are classified as Plant Species with Extremely Small Populations (PSEP) and are endangered. Despite sharing similar morphological traits and habitat preferences, T. magnifica and T. exalata exhibit marked differences in floristic composition, community structure, and population dynamics, reflecting contrasting life‐history strategies and degrees of habitat specialization. By integrating analyses of floristic contribution, species associations, and demographic patterns, our findings highlight the importance of habitat context in shaping the persistence of narrowly endemic understory plants. Our results demonstrate that even closely related endangered species can adopt divergent ecological strategies. Tigridiopalma magnifica persists through broad biotic associations but appears constrained by seedling establishment, likely due to dense leaf litter or intense understory competition. In contrast, T. exalata relies on specific canopy tree associations but shows signs of reproductive limitation within resource‐poor niches. Effective in situ conservation therefore requires a shift from a species‐centric to an interaction‐centric framework, emphasizing the management of community processes rather than target species alone, specifically, facilitative interactions for T. magnifica and canopy filtering mechanisms for T. exalata .