[Botany • 2025] Lysimachia nanshanensis (Primulaceae) • A New Species from southwest Hunan, China

Lysimachia nanshanensis C.Xiong & S.R.Yi, 

in Xiong, Wang, Fu, Luo, Huang, Zhang et Yi, 2025.

南山落地梅  ||  DOI: doi.org/10.3897/phytokeys.262.153293 

Abstract

Lysimachia nanshanensis, a new species of Lysimachia ser. Paridiformes discovered in Nanshan National Park of southwest Hunan, China, is described and illustrated. Morphologically, this new species most closely resembles L. sciadantha in having whorled leaves and terminal umbels but differs from L. sciadantha by having terminal umbels without a peduncle, subpapery leaves with obvious black glandular punctation and striation, longer pedicels, and filaments that are nearly free. Results of molecular phylogenetic analysis, based on nuclear ribosomal internal transcribed spacer (nrITS) and two chloroplast DNA fragments (matK and rbcL) of 34 Lysimachia species, showed that L. nanshanensis is closely related to L. sciadantha. According to the IUCN Red List Categories and Criteria, the new species is assigned to the Vulnerable (VU D1) category.

Key words: Flora of Hunan, morphology, Nanshan National Park, taxonomy 

Lysimachia nanshanensis C.Xiong & S.R.Yi.
A, B. Habit; C. Terminal umbels; D. Flower (front view); E. Flower (back view); F. Flower buds; G. Flower (side view); H. Abaxial of calyx; I. Adaxial side of corolla; J. Stamens; K. Pistil.

 Lysimachia nanshanensis C.Xiong & S.R.Yi, sp. nov.

 

Diagnosis. Lysimachia nanshanensis belongs to ser. Paridiformes F.H.Chen & C.M.Hu (Chen and Hu 1979: 36) and is similar to L. sciadantha C.Y. Wu (Wu 1965: 53) by sharing some morphological characters, such as the middle and lower leaves bract-like and opposite, upper leaves clustering at the stem top, flowers densely on umbel. But differs from L. sciadantha in leaves 4–6 (vs. 4) in a whorl, subpapery (vs. stiffly papery), elliptic, ovate to obovate (vs. elliptic), apex obtuse to mucronate (vs. acute to short acuminate), umbels terminal without peduncle (vs. peduncle 1.8–6 cm long), pedicel 3–6 cm (vs. 1.2–2.5) long, filaments almost free (vs. base tube 3–3.5 mm).

Etymology. The specific epithet ‘nanshanensis’ refers to the type locality where the new species was found, Nanshan National Park, Southwest Hunan. The Chinese name is “南山落地梅 (nán shān luò dì méi)”.

 Chi Xiong, Xiao Wang, Xiao-Ying Fu, Kang Luo, Ya Huang, Hong-Jing Zhang and Si-Rong Yi. 2025. Lysimachia nanshanensis (Primulaceae), A New Species from southwest Hunan, China. PhytoKeys. 262: 191-202. DOI: doi.org/10.3897/phytokeys.262.153293