Lysimachia ailaoshanensis (Primulaceae), a new species from Yunnan, China

Hai-Fei Yan; Gang Hao

doi:10.3897/phytokeys.246.130838

Research Article

Lysimachia ailaoshanensis (Primulaceae), a new species from Yunnan, China

Hai-Fei Yan^‡, Gang Hao^§

‡ South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China

§ South China Agricultural University, Guangzhou, China

Corresponding author: Gang Hao ( haogang@scau.edu.cn )

Academic editor: Bing Liu

This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Citation: Yan H-F, Hao G (2024) Lysimachia ailaoshanensis (Primulaceae), a new species from Yunnan, China. PhytoKeys 246: 277-282. https://doi.org/10.3897/phytokeys.246.130838

Abstract

A new species, Lysimachia ailaoshanensis is described and illustrated. In gross morphology it is evidently allied to subgen. Palladia sect. Chenopodiopsis and is most similar to L. chenopodioides and L. remotiflora, but is distinguished from L. chenopodioides by narrower lanceolate leaf blade and longer pedicel, and longer stamens and styles, and from L. remotiflora by narrower leaf blade and longer stamens.

Key words

Ericales, flora, morphological features, taxonomy, Yunnan

Introduction

Ailao Mountain, located in central Yunnan, China, has rich plant diversity and was designated as a national natural reserve in 1988. In August 2020, Dr. H.F. Yan and colleagues of South China Botanical Garden made a botanical excursion to Ailao Mt., collecting plants of this area for systematic study on Primulaceae. A putatively new species of Lysimachia was secured. A subsequent field trip was conducted to confirm its entity. Careful examination revealed that the plant is distinct from all other Lysimachia species and represents an undescribed taxon.

Materials and methods

Earlier taxonomic literature has been consulted (e.g. Handel-Mazzetti 1928; Chen and Hu 1979; Chen et al. 1989; Hu 1985, 1992, 1999; Hu and Kelso 1996) to infer allied species and relatedness. The new species was examined in the field and at the herbarium, and measurements of morphological features were conducted with fresh specimens. Flowers were dissected and measured in the laboratory. Morphological comparison with similar species was performed based on living plants and specimens from IBSC, KUN, PE, IBK and from the images of specimens from the JSTOR Global Plants (http://plants.jstor.org/). The conservation status of the new species was assessed following the guidelines for using the IUCN Red List Categories and Criteria (IUCN Standards and Petitions Committee 2024).

Taxonomic treatment

Lysimachia ailaoshanensis G.Hao & Y.F.Yan, sp. nov.

urn:lsid:ipni.org:names:77348638-1

Figs 1, 2

Type

China. • Yunnan Province, Jingdong Yi Autonomous County, Xujiaba, near Damenkou; 24°31'N, 101°00'E; alt. 2363 m; 14 Aug. 2020; Hai-Fei Yan et al. Y2020286 (holotype: IBSC! barcode IBSC1021506; isotypes: IBSC! barcode IBSC1025535, IBSC1025536).

Diagnosis

Lysimachia ailaoshanensis is most similar to L. chenopodioides Watt ex Hook. f. and L. remotiflora C.M. Hu, but differs from L. chenopodioides in narrower lanceolate leaf blade and longer pedicel, and longer stamens and styles, and from L. remotiflora in narrower leaf blade and longer stamens.

Description

Herbs annual, glabrous, 18 to 58 cm tall. Stems erect to ascending-erect, quadrangular, branches usually few above middle. Leaves alternate; petiole 1–2.8 cm long, narrowly winged; leaf blade narrowly lanceolate, 1.8–6.0 × 0.5–1.5 cm, sparsely dark purple or brown glandular punctate, base attenuate, apex acuminate to acute. Pedicel 0.5–2 cm long. Flowers in axils of upper leaves, always forming a raceme of 5–18 cm, lax. Calyx lobes lanceolate, 4.5–5.5 mm long, split nearly to base, dark purple or black glandular striate outside, apex obtuse to subacute. Corolla white or pink; tube ca. 1 mm long; lobes oblong-spatulate, 4.5–5 mm long, dark purple glandular striate, apex obtuse. Stamens ca. as long as to slightly shorter than corolla lobes; filaments adnate to base of corolla lobes, free parts ca. 4.0 mm; anthers ovate, dorsifixed, ca. 0.5 mm. Ovary glabrous; style ca. 4.5 mm. Capsule globose, ca. 4 mm in diameter, glabrous.

Distribution and habitat

The new species is presently known only from the type locality in Yunnan Province, Jingdong Yi Autonomous County (Map 1). It grows at the edge of secondary mixed-evergreen forests.

Map 1.

Location of the population of Lysimachia ailaoshanensis in Jingdong, Yunnan.

Phenology

Flowering from June to August, fruiting from July to August.

Etymology

The new species is named referring to the type locality where the new species occurs, Ailaoshan National Nature Reserve, Yunnan, China.

Conservation status

Based on our field investigations in Jingdong Yi Autonomous County and adjacent areas in the past three years, only one population with only five individuals of the new species have been found in an area of 10 km² in Jingdong Yi Autonomous County. Moreover, the local habitat is under threat by road construction and tourism development. Therefore, the conservation status of the new species is assessed as Critically Endangered (CR) (B2a & bi, iii), according to the guidelines for using the IUCN Red List Categories and Criteria (IUCN Standards and Petitions Committee 2024).

Additional specimens examined (paratype)

China. The same locality as holotype, 7 August 2023, Hai-Fei Yan Yan2023054 (IBSC! barcode IBSC1025537, IBSC1025538).

Relationship with similar species

Based on the classification of Lysimachia by Handel-Mazzetti (1928) and Chen and Hu (1979), the new species clearly belongs to Lysimachia subg. Palladia sect. Chenopodiopsis Hand.-Mazz., which is characterised by leaves alternate, racemes sparsely flowered or solitary in axils of upper leaves, filaments free, adnate to middle of corolla, and styles usually shorter than corolla. Approximately eight species were recognized in this section, mainly distributed in southwestern China and adjacent regions (e.g., Bhutan, India, Kashmir, N. Myanmar, Nepal, Pakistan), and a few outliers in Thailand, the Mediterranean coast, and southeastern Africa (Handel-Mazzetti 1928; Chen et al. 1989; Hu and Kelso 1996). The new species is morphologically similar to L. chenopodioides and L. remotiflora, but is distinctive in its leaf shape and heights of stamens and styles (see Table 1, Figs 1–3).

Table 1.

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Main morphological differences between Lysimachia ailaoshanensis and two similar species.

Features	L. ailaoshanensis	L. chenopodioides	L. remotiflora
Petiole length	1–2.8 cm	0.5–1 cm	ca. 1.1 cm
Lamina shape	narrowly lanceolate	ovate to rhomboid-ovate	ovate-lanceolate
Pedicel length	0.5–2 cm	1–2 mm	1.5–2.5 cm
Filament length	4.5–5 mm	1–1.5 mm	1–1.5 mm
Style length	4.5 mm	1.5 mm	2.5 mm

Figure 1.

Lysimachia ailaoshanensis G.Hao & Y.F.Yan, sp. nov. A habit B abaxial (right) and adaxial (left) surfaces of a leaf C flower D calyx lobes E dissected corolla F pistil and its stigma (enlarged) G young fruit with persistent calyx. Drawn by Yun-Xiao Liu from the holotype.

Figure 2.

Living plant of Lysimachia ailaoshanensis G.Hao & Y.F.Yan, sp. nov. A habitat B habit C leaves on abaxial (right) and adaxial (left) surfaces D flower (lateral view) E corolla F pistil G abaxial (left) and adaxial (right) sides of a calyx lobe. Photographed by Hai-Fei Yan.

Figure 3.

Holotypes of Lysimachia ailaoshanensis and two of its allies A L. ailaoshanensis B L. chenopodioides C L. remotiflora.

Acknowledgements

We thank Yun-Xiao Liu for the line drawings of the holotype, and Kai-Yong Lu from Ailaoshan National Natural Reserve for field assistance.

Additional information

Conflict of interest

The authors have declared that no competing interests exist.

Ethical statement

No ethical statement was reported.

Funding

The study was financially supported by the National Natural Science Foundation of China (grants no. 32070220, 32470223) and the Biological Resources Programme, Chinese Academy of Sciences (KFJ-BRP-017-104).

Author contributions

All authors have contributed equally.

Data availability

All of the data that support the findings of this study are available in the main text.

References

Chen FH, Hu CM (1979) Taxomomic and phytogeographic studies on Chinese species of Lysimachia. Acta Phytotaxonomica Sinica 17: 21–53.

Chen FH, Hu CM, Fang YY, Zheng CZ (1989) Lysimachia. In: Chen FH, Hu CM (Eds) Flora Reipublicae Popularis Sinicae. Vol. 59 (1). Science Press, Beijing, 3−133.

Handel-Mazzetti H (1928) A revision of the Chinese species of Lysimachia. Notes from the Royal Botanic Garden Edinburgh 77: 51–122.

Hu CM (1985) Further notes on the genus Lysimachia L. in mainland S.E. Asia. Acta Phytotaxonomica Sinica 23: 355–368.

Hu CM (1992) Primulaceae. In: Morat P (Ed.) Flore du Cambodge du Laos et du Viêtnam, Vol. 26. Association de Botanique Tropicae, Paris, 115–144.

Hu CM (1999) Primulaceae. In: Santisuk T, Larsen K (Eds) Flora of Thailand. Vol. 7(2). The Forest Herbarium, Royal Forest Department, Bangkok, 155−168.

Hu CM, Kelso S (1996) Primulaceae. In: Wu ZY, Raven PH (Eds) Flora of China. Vol. 15. Science Press, Beijing, and Missouri Botanical Garden Press, St Louis, 99–185.

IUCN Standards and Petitions Committee (2024) Guidelines for using the IUCN Red List categories and criteria. Version 16: Prepared by the Standards and Petitions Committee in March 2024.

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