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| Hedyotis longiramulis Y.D.Xu & R.J.Wang, in Xu, Zhang et Wang, 2023. |
Abstract
Hedyotis longiramulis sp. nov. (Rubiaceae) is described from Guangdong Province, China. It is similar to H. caudatifolia but differs in having puberulent, more or less tetragonal and decussately sulcate juvenile stems, waxy leaf surface, short inflorescence peduncles, high length ratio of corolla lobe to tube, and subglobose capsules. The phylogenetic analysis reveals that H. longiramulis is sister to H. pubirachis. Dimorphism concerning pollen size was observed in the heterostylous flowers. The complete chloroplast genome of the new species comprises a typical quadripartite structure of 153,616 bp in length, with two inverted repeats of 25,457 bp, a large single-copy of 85,050 bp and a small single-copy of 17,652 bp. It contains 112 unique genes, including 79 protein-coding genes, 29 tRNA genes, and four rRNA genes, the GC content of the chloroplast genome is 32.4%. The new species is provisionally evaluated as “Least Concern” because it is common and well-protected in two Provincial Nature Reserves.
Key words: Chloroplast genome, Hedyotis-Oldenlandia complex, phylogeny, taxonomy
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| Hedyotis longiramulis Y.D. Xu & R.J. Wang A habit B habitat C inflorescences D part of stem (right) and its transverse section E adaxial (left) and abaxial (right) surgaces of leaf F Stipules G long-styled flower (left) and its longitudinal section (right) H short-styled flower (left) and its longitudinal section (right) I infructescence J diplophragmous capsule K dorsal (left) and ventral (right) view of seeds. |
Hedyotis longiramulis Y.D.Xu & R.J.Wang, sp. nov.
鹅凰嶂耳草 (é Huáng Zhàng ěr Căo)
Diagnosis: The species is similar to H. caudatifolia in having a subshrubby habit, ovate to lanceolate leaves, and long lateral branches with several terminal and axillary inflorescences, but differs from it by having puberulent, more or less tetragonal and decussately sulcate juvenile stems (versus glabrous and terete in H. caudatifolia), waxy leaf surface (versus non-waxy in H. caudatifolia), shorter peduncles (0.5–2.0 cm versus 2.0–10.0 cm in H. caudatifolia), a higher length ratio of corolla lobe to tube (0.9–1.0 versus approximately 0.8 in H. caudatifolia), and subglobose capsules (versus ellipsoid-oblong or ellipsoid in H. caudatifolia).
Etymology: The specific epithet “longiramulis” of the new species refers to its long lateral branches bearing many inflorescences.
Yi-Da Xu, Ying Zhang and Rui-Jiang Wang. 2023. Hedyotis longiramulis (Rubiaceae), A New Species from south China. PhytoKeys. 230: 271-287. DOI: 10.3897/phytokeys.230.87675
