﻿Aletrisguangxiensis (Nartheciaceae), a new species from Guangxi, China

﻿Abstract Aletrisguangxiensis Y. Nong & Y. F. Huang (Nartheciaceae), a new species from Guangxi, China, is described and illustrated. This new species is most similar to A.scopulorum, but it can be easily distinguished by its sparsely glandular, 5–18 cm long scape, glandular inflorescence axis, distinctly pedicellate flowers, sparsely glandular, 5–10 mm long pedicel, bract borne at base of pedicel, glabrous perianth divided to the base, strongly recurved or revolute perianth lobes and turbinate, obovoid to oblong-obovoid capsule. An identification key for 24 species and 1 hybrid of Aletris is also provided.


Introduction
The family Nartheciaceae Fr. ex Bjurzon comprises five genera (Caddick et al. 2002).All species in this family are perennial herbs with short tuberculate or creeping rhizomes, erect stems and terminal spikes or racemes.Various researchers have continuously enhanced its classification (Li andZhang 2011, Fuse et al. 2012;Tobe et al. 2018).In this family, Aletris L. is the largest genus, which contains approximately 21 species distributed in East Asia and North America (Zhao et al. 2012).However, a total of 23 species and 1 hybrid have been accepted according to the Plants of the World Online (POWO 2023).
The genus Aletris is characterised by perennial herbs with leaves in basal rosettes, lanceolate to linear blades, racemose to spicate inflorescences, scape simple, erect, usually with a few small, bractlike leaves, flowers bisexual, perianth white, yellow, or golden orange, cylindrical, campanulate or obovoid, with rough abaxial surfaces, six basally connate tepals, six stamens with basifixed anthers, obscurely 3-lobed stigma and fruits capsular, 3-locular, beaked.During our field surveys in Guangxi in 2020, we found an unusual Aletris population that was morphologically similar to the species A. scopulorum Dunn.However, this special population is distinctly different from A. scopulorum, based on sparsely glandular, 5-18 cm long scape, glandular inflorescence axis, distinctly pedicellate flowers with sparsely glandular, 5-10 mm long pedicel, glabrous perianth divided to the base, strongly recurved or revolute perianth lobes and turbinate, obovoid to oblong-obovoid capsule (Table 1).Therefore, we proposed that this special population may represent a new species.In order to test this hypothesis, we conducted a literature search (Noltie 1994;Yang 1997;Liang and Turland 2000) and examined many specimens of Aletris from the Herbaria PE, IBK, GXMI and KUN.Finally, we continued to carry out multiple rounds of field surveys to confirm that this special population represents a new species.

Materials and methods
The new species were described based on field observations that were conducted in March to May and examination of herbarium specimens at GXMI.Other related Aletris species were examined based on online images from Kew Herbarium Catalogue (http://apps.kew.org/herbcat/gotoHomePage.do) and JSTOR Global Plants (http://plants.jstor.org/)and Chinese Virtual Herbarium (https://www.cvh.ac.cn/).Morphological characters that distinguish it from all other species in the genus of Aletris are used.We also observed living plants of the new species at flowering and fruiting time (March to May).We observed characters of stems, leaves, pedicels, flowers, receptacles, petals, stamens, gynoecium, carpels, size of flowers, size and shape of petals, number of stamens and the shape of gynoecium and fruit.
Descriptions were written from herbarium specimens.Measurements were made with a tape measure and calipers.The structure of the indumentum and its distribution were observed and described under a dissecting microscope at magnifications of more than 20×.Additional information on locality, habitat, ecology, plant form and fruits were collected in the field and taken from herbarium labels.Conservation threat assessment followed IUCN Categories and Criteria (IUCN 2022).Diagnosis.Aletris guangxiensis is most similar to A. scopulorum, but it differs by inflorescence axis sparsely glandular (vs.pubescent), pedicel 5-8 mm (vs.0.5-3.5 mm), bract borne at base of pedicel (vs.bract borne on the proximal 1/2 of the pedicel), lobes strongly recurved or revolute, linear, 4-7 × 0.2-0.5 mm (vs.erect or slightly recurved, narrowly oblong-lanceolate to linear, 1.5-2.5 × 0.3-0.7 mm).At first glance, it also looks similar to A. gracilis Rendle and A. cinerascens Wang & Tang, but differs by its inflorescence axis sparsely glandular (vs.glabrous), pedicel 5-8 mm (vs.1-10 mm), perianth white (vs.yellowish, whitish or pinkish/ yellowish).More detailed morphological differences amongst the four species are provided in Table 1.
Phenology.Flowering and fruiting in March to April.Etymology.Guangxi is located in the southwest of China and is a biodiversity hotspot where many new species or new species records have been found (Hu et al. 2019;Luo et al. 2020;Feng et al. 2021;Xin et al. 2021;Huang et al. 2022;Nong et al. 2023).The new species, A. guangxiensis, is found in this region and is named after the geographic location.Distribution and habit.Known only from the southeast of Guangxi, China (Fig. 5).The new species mainly occurs at elevations of 320 m.It has been mainly found on moist cliffs next to streams.
IUCN Red List Category.Data available for the new species are still insufficient to assess its conservation status.According to the IUCN Criteria (IUCN 2022), it is considered Data Deficient (DD) until more information becomes available.Although the population of A. guangxiensis is currently in relatively good conditions, further collection and monitoring are necessary to allow more conclusive estimations about the rarity and vulnerability of the species.Therefore, special attention should be given to the conservation of the new species of Aletris.

Figure 1 .
Figure 1.Habitat of Aletris guangxiensis on the moist cliffs next to streams.[Photographed by You Nong and Ke-Jian Yan].

Figure 2 .
Figure 2. Line drawing of Aletris guangxiensis A flowering branch B flowers C Ovary and stigma D Filaments of stamens and perianth [Drawn by Xin-cheng Qu from Y Nong NY2020042301 (GXMI)].

Figure 3 .
Figure 3. Aletris guangxiensis A flower (front view) B, C flower (lateral view) D ovary and stigma E young fruit F inflorescence node with flower-subtending bract and flower bud, pedicel with bracteole in its proximal part G inflorescence H flowers I plant [Photographed by Ke-Jian Yan from G.Y. Wei WGY2023033001 (GXMI), edited by Yuan Fang].