Primula lizipingensis W.B.Ju, L.Y.He & X.F.Gao, 2023

Ju, Wen-Bin, He, Liu-Yang, Lan, Qi, Wu, Ying-Hao, Deng, Heng-Ning, He, Xing-Jin, Gao, Xin-Fen & Xu, Bo, 2023, Primula lizipingensis (Primulaceae), a new species from Sichuan, China, PhytoKeys 236, pp. 135-143 : 135

Primula lizipingensis W.B.Ju, L.Y.He & X.F.Gao sp. nov.

Figs 1 , 2 , 3

Diagnosis.

Primula lizipingensis is morphologically similar to P. rhodochroa and P. socialis . However, the new species can be easily distinguished from P. rhodochroa by its leaf margin sharply dentate above the middle, scape absent, flower solitary subtended by a single, linear-lanceolate to subulate bract, the calyx lobes split to the middle, the corolla tube longer than the calyx, and its interior has white hairs. Compared with P. socialis , the new species is covered with white farinose (vs. glabrous), leaf oblanceolate to spathulate, and papery when dry (vs. obovate-elliptic to oblanceolate, membranous when dry), bracts linear-lanceolate to subulate (vs. linear), calyx lobes split to the middle (vs. split to the middle or below), and corolla tube hairy inside (vs. glabrous).

Type.

China. Sichuan: Shimian county, Liziping National Nature Reserve , growing in moist rock crevices covered with moss ; 29°00′N, 102°11′E, 4318 m alt., 18 May 2023 (fl.), Liuyang He J-1201 (holotype CDBI!; isotypes KUN!)

Description.

A dwarf farinose tufted perennial herb, at most 2.5 cm tall, with a short stout rhizome and covered at the base by the withered remains of old leaves of the previous year. Leaves forming a dense tuft, papery when dry, including the petiole 5-12 mm long, 2.5-5.5 mm broad, oblanceolate to spathulate, rounded or acute at apex, tapering into the papery winged petiole which when fully developed is as long as the leaf blade, margin sharply dentate above the middle, green above with a thin covering of potentially white farinose glands, thickly covered below with white farina, the midveins and lateral veins are prominent at abaxially. Scape almost obsolete, bearing one flower. Bracts solitary, at base, linear-lanceolate to subulate, more or less white farinose, 1-2.8 mm long. Flower solitary, heterostylous. Pedicels 1.5-5.0 mm long, cover the white farinose, not extended in fruit. Calyx green, campanulate, 5-5.5 mm long, farinose both within and without, prominently 5-veined, split to the middle, lobes narrowly triangular to lanceolate, apex acute. Corolla obscurely annulate, with sparsely white farinose glands abaxially; limb 14-18 mm across, funnelform; tube deep purple, 1.3-1.8 times the length of the calyx and a few white hairs adaxially; lobes pale purple with a white eye, spreading, 6.5-8.2 × 4.5-6.0 mm, broadly obovate, deeply emarginate. Pin flowers: corolla tube 7-8 mm long, widely ampliated above the insertion of stamens; stamens ca. 1.5 mm above base of corolla tube; style ca. 2/3 as long as tube. Thrum flowers: corolla tube ca. 8 mm long, widely ampliated above insertion of stamens; stamens inserted slightly above the middle of corolla tube; style ca. 2 mm. Capsule oblong, slightly shortly than the calyx.

Phenology.

Flowering occurs in May, fruiting is unknown.

Distribution and habitat.

Primula lizipingensis is only known from the type locality Liziping National Nature Reserve, Shimian County, Sichuan, China. It grows in moss-covered limestone crevices at an altitude of 4300-4400 meters.

Etymology.

The specific epithet ‘lizipingensis’ refers to the type locality where the new species occurs, Liziping National Nature Reserve, Sichuan, China.

Conservation status.

Data Deficient (DD). Due to insufficient field investigations, we do not yet have a clear understanding of its natural distribution and population status, nor do we have enough information to directly or indirectly assess its risk of extinction. Therefore, we temporarily categorize this species as Data Deficient according to the International Union for Conservation of Nature Red List Categories ( IUCN Standards and Petitions Committee 2022). Further field investigations in the high-altitude areas of western Sichuan in the future can provide more information about its abundance and distribution.

Discussion.

The section Primula Aleuritia was originally considered by Duby (1844) with citation of type species P. farinosa L. This section is a large group having more than 80 species with wide distribution. The distribution is almost throughout the range of the genus Primula , spanning across circum-arctic regions and major mountain systems in Europe, North America, and Asia ( Hu 1990, 1994; Hu and Kelso 1996). Notably, this is the sole section of the Primula genus that includes representative species in South America ( Hu 1994; Basak et al. 2014). In this study, we followed Hu’s (1990) taxonomic treatment of the Primula in China.

Further research indicates that this new species is similar to P. rhodochroa and P. socialis in that they have dwarf farinose plant, possess short rhizomes, and produce solitary flowers emerging from basal rosettes. P. rhodochroa , distributed in southeast Xizang, thrives in wet moss on boulders or rock faces at altitudes of 4000-5000 meters. P. socialis , found in western Yunnan, flourishes in shady crevices of mountain rocks at an altitude of 2950 m. P. lizipingensis , found in Shimian County, Sichuan Province, on the eastern edge of the Hengduan Mountains, grows in moss-covered limestone crevices at an altitude of 4300-4400 m. Despite all three growing in limestone dam crevices with moss, prolonged geographical isolation has led to morphological differentiation, resulting in the emergence of distinct species. The same situation also occurs in the morphological and habitat similarities between P. kialensis Franchet and P. yunnanensis subsp. membranifolia (Franchet) Halda. These species are both covered with yellow farinose and showing resemblances in leaf morphology, and inflorescence. The main difference is that P. yunnanensis subsp. membranifolia has a corolla tube length 2-4 times that of the calyx, and its leaves texture is membranous, whereas P. kialensis has a corolla tube length 1-2 times that of the calyx and chartaceous leaves. The former is distributed in counties such as Jiulong, Kangding, and Lixian, located in the eastern part of the Hengduan Mountains, and belongs to a unique species in Sichuan. The latter is distributed in counties such as Dali, Yangbi, and Fengqing, located in the central and western parts of the Hengduan Mountains, and belongs to a unique species in Yunnan. The new species differs from P. rhodochroa in the characteristic of leaf margin teeth, the presence or absence of scape, the characteristic and numbers of bracts, the split degree of calyx lobes, and the presence of hairs inside the corolla tube. Morphologically, the new species is more closely related to P. socialis because both are characterized by having solitary flower and bract, without a scape, but easily recognized by the present of white farina covering the whole plant, leaves smaller and papery after drying with margin sharply dentate, the bract linear-lanceolate to subulate, and hairy with white hairs inside the corolla tube. A detailed comparison of the three species is shown in Table 1 .

Figures

Figure 1. Habitat of the Primula lizipingensis sp. nov. (A-D).

Figure 2. Primula lizipingensis sp. nov. A fresh plants B leaves C pin flower (showing flower side and front, the position of anthers and styles in the tube) D thrum flower (showing flower side and front, the position of anthers and styles in the tube) E plants base F calyx, capsule and mature fruit that has already split G bracts. Photographs by W-BJ.

Figure 3. Primula lizipingensis sp. nov. A habit B leaves C inflorescence and front of the flower D bracts E pin flowers (left) and thrum flowers (right) F calyx and pistil of pin flowers (left) and thrum flowers (right). Drawn by Z-LL.