Hansenia Turcz., Haplosphaera Hand.-Mazz. and Sinodielsia H.Wolff are three Apiaceae genera endemic to the Hengduan Mountains and the Himalayas, which usually inhabit elevations greater than 2000 m. The phylogenetic relationships between and within the genera were uncertain, especially the placement of Hap. himalayensis and S. microloba. Therefore, we aimed to conduct comparative (simple sequence repeat (SSR) structure, codon usage bias, nucleotide diversity (Pi) and inverted repeat (IR) boundaries) and phylogenetic analyses of Hansenia, Haplosphaera and Sinodielsia (also compared with Chamaesium and Bupleurum) to reduce uncertainties in intergeneric and interspecific relationships. We newly assembled eight plastid genomes from Hansenia, Haplosphaera and Sinodielsia species, and analyzed them with two plastid genomes from GenBank of Hap. phaea,S. yunnanensis. Phylogenetic analyses used these ten genomes and another 22 plastid genome sequences of Apiaceae. We found that the newly assembled eight genomes ranged from 155,435 bp to 157,797 bp in length and all had a typical quadripartite structure. Fifty-five to 75 SSRs were found in Hansenia, Haplosphaera and Sinodielsia species, and the most abundant SSR was mononucleotide, which accounted for 58.47% of Hansenia, 60.21% of Haplosphaera and 48.01% of Sinodielsia. There was no evident divergence of codon usage frequency between the three genera, where codons ranged from 21,134 to 21,254. The Pi analysis showed that trnE(UUC)-trnT(GGU), trnH(GUG)-psbA and trnE(UUC)-trnT(GGU) spacer regions had the highest Pi values in the plastid genomes of Hansenia (0.01889), Haplosphaera (0.04333) and Sinodielsia (0.01222), respectively. The ndhG-ndhI spacer regions were found in all three genera to have higher diversity values (Pi values: 0.01028–0.2), and thus may provide potential DNA barcodes in phylogenetic analysis. IR boundary analysis showed that the length of rps19 and ycf1 genes entering IRs were usually stable in the same genus. Our phylogenetic tree demonstrated that Hap. himalayensis is sister to Han. weberbaueriana; meanwhile, Haplosphaera and Hansenia are nested together in the East Asia clade, and S. microloba is nested within individuals of S. yunnanensis in the Acronema clade. This study will enrich the complete plastid genome dataset of the Apiaceae genera and has provided a new insight into phylogeny reconstruction using complete plastid genomes of Hansenia, Haplosphaera and Sinodielsia.

Tordyliopsis is a monotypic genus within the family Apiaceae and is endemic to the southern margin of the Himalayas. The type species, Tordyliopsis brunonis, is easily distinguished by its lanceolate bracts and bracteoles. In this study, we used both phylogenetic and morphological analyses to investigate the relationship between T. brunonis and other species in the Apiaceae. Our phylogenetic analyses of ITS sequences and 79 coding sequences from complete plastid genomes revealed that T. brunonis is nested with Semenovia species. Additionally, our morphological analysis showed that Tordyliopsis and Semenovia share several similar features, including elliptic or oblong mericarps with widely spaced dorsal ribs, broader and winged marginal ribs with slightly inflated distal parts, clavate vittae, and domed stylopodium. Based on these results, we propose that the monotypic genus Tordyliopsis should be transferred to Semenovia.

The study reanalyzed the morphology (especially fruits) and phylogeny (based on nrITS and plastid DNA rpl16 and rps16 intron sequences) of S. filicinum and its related species aiming to resolve taxonomic uncertainties. The results showed that Meeboldia achilleifolia, M. delavayi, M. linearis, M. microloba and S. filicinum constitute a well-supported monophyly in nrITS and plastid DNA trees. We found that S. filicinum is distinct from other Sinocarum species including S. vaginatum, S. cruciatum and the type S. coloratum in all trees. Concern morphology, S. filicinum is more similar to Meeboldia species, rather than S. coloratum in plant height, fruit size, number of vallecular vittae and commissural vittae. The authors propose that S. filicinum be transferred to Meeboldia and be renamed as Meeboldia filicina (H.Wolff) W.Gou, Y.P.Xiao & X.J.He.

Physospermopsis deqinensis X.L.Guo & X.J.He, a new species from Deqin County, Yunnan, China, is described and illustrated. It resembles P. rubrinervis and P. shaniana by having leaf-like bracts and bracteoles with purplish margins, but differs in its stems 3–5 mm thick, pinnately divided bracts, longer bracteoles, umbels with 13–20 rays, and oblong to ovoid mericarps with linear, slightly sinuate ribs. The new species also has more vittae per furrow (3–4) and an irregular endosperm that is ventrally concave and dorsally undulate. Phylogenetic analyses using nrITS and plastid introns (rpl16, rps16) place P. deqinensis as sister to the clade comprising P. delavayi and P. alepidioides in the nuclear tree, and sister to a clade of six Physospermopsis species in the plastid tree. The species is currently known only from the Biluo Snow Mountains, Yunnan, and is preliminarily assessed as Data Deficient (IUCN).