Primulina jiulianshanensis F.Wen & G.L.Xu, 2023

Xu, Guo-Liang, Liang, Li-Fen, Chen, Di-Ya, Jing, Zhi-Fang, Zuo, Xiao-Hai, Zuo, Zheng-Yu & Wen, Fang, 2023, Primulina jiulianshanensis, a new species of Gesneriaceae from Jiangxi Province, China, PhytoKeys 226, pp. 1-16 : 1

Primulina jiulianshanensis F.Wen & G.L.Xu sp.nov.

Figs 2 , 3

Diagnosis.

This new species differs from P. wenii by the combination of the following characteristics: petiole, both sides of leaf blades, adaxial surface of the calyx lobes, corolla inside toward the bottom, bract margins glandular-pubescent (vs. what above-mentioned eglandular-pubescent in P. wenii ); lateral bracts 4-9 × ca. 2 mm, the central one 2-5 × 1-1.5 mm, adaxially glabrous but sparsely pubescent at apex (vs. lateral bracts 14-16 × 2.5-3.0 mm, the central one 10-12 × 1.3-1.6 mm, all adaxially pubescent); calyx lobes 8-11 × ca. 2 mm, each side with several brown serrate teeth at apex (vs. 14-15 × ca. 2.5 mm and entire); filaments and staminodes sparsely glandular-puberulent (vs. glabrous). Detailed morphological comparisons with P. wenii are provided in Table 3 .

Holotype.

China, Jiangxi Province: Ganzhou City, Longnan County, Jiulianshan National Nature Reserve, growing in shady and moist cliffs in the forest, 24°34'8.9"N, 114°25'49.7"E, altitude ca. 440 m, April 20, 2021, Guo-Liang Xu, JLSXGL-20210420 (Holotype IBK!; Isotype: KUN!)

Description.

Herbs perennial, acaulescent, rhizome terete, 1-4 cm long, 0.8-1.5 cm in diam., leaves all basal, 4-8, petiole 10-40 × 4-13 mm, densely villous and very sparsely glandular-pubescent. Leaf blade oblong-elliptic or broadly elliptic, 4-13 × 4-8 cm, thickly chartaceous, more and less fleshly, adaxially pale green to dark green, densely white to light red villous and very sparsely glandular-pubescent, abaxially pale green, densely white villous and pubescent, and very sparsely glandular-pubescent, base apparently asymmetric but cuneate, margin irregularly obtuse-serrate, apex slightly obtuse, lateral veins 4-6 on each side, adaxially inconspicuously sunken, abaxially prominently raised. Inflorescence dichotomous cymes 2-4, axillary, 1-3-branched, 3-9-flowered or more; peduncle and pedicle green, erectly white or light red pubescent; peduncle 5-10 cm long, 2-3 mm in diam.; pedicle 5-15 mm long, 1-2 mm in diam. Bracts 3, lanceolate or spatulate, a pair on either side in same size, opposite, 4-9 mm long, ca. 2 mm wide, the middle one smaller, 2-5 mm long, 1-1.5 mm wide, all three abaxially white or reddish pubescent, adaxially glabrous but sparsely pubescent at apex, margin entire, ciliate and very sparsely glandular-puberulent, apex acute; bracteoles 3, shape and indumentum same as bracts, 2-5 mm long, 1-1.5 mm wide. Calyx 5-parted, lobes lanceolate, 8-11 mm long, ca. 2 mm wide, nearly equal, abaxially densely white or light red villous, adaxially sparsely white puberulent and glandular-puberulent, margin entire but each side of calyx lobes with 1-3 purplish brown crenate at the apex. Corolla pinkish purple to bluish purple, 3.6-4.0 cm long; corolla tube funnelform, 2.6-3 cm long, mouth 1.3-1.6 cm in diam., base ca. 5 mm in diam., outside densely glandular-pubescent, inside from the middle to the base sparsely glandular-puberulent, and the upper part of the corolla tube glabrous; corolla tube abdomen with two obviously longitudinal ridges, the upper part (close to the mouth) of the longitudinal ridge dark bluish purple, and the lower part (close to the bottom) changing into yellowish brown; a dark reddish-brown lump on the upper throat of the corolla tube inside and between upper lip lobes, ovate to spatulate, extending to the middle of the corolla tube, the lump densely glandular-puberulent; a narrow triangular thickened dark reddish-brown stripe extending to the middle of the corolla tube inside at each side of corolla tube and at the junction of the abaxial and adaxial lip; limb distinctly 2-lipped, adaxial lip 2-parted to the middle, lobes broadly ovate to semicircular, apex round, 6-8 mm long, 6-9 mm wide at the bottom; abaxial lip 3-parted to near the base, lobes elliptical to oblong, 8-12 mm long, 7-9 mm wide at the bottom. Stamens 2, adnate to 1.8 cm above the base of corolla tube; filaments linear, yellow from middle to base but white upper half, 8-11 mm long, geniculate near the base, glandular-puberulent; anthers reniform, slightly constricted at the middle, densely villous and fewer glandular-puberulent; staminodes 3, yellowish, lateral ones ca. 6 mm long, adnate to 14 mm above the base of corolla tube, straight, linear, very sparsely glandular-puberulent, apex capitate, the central one ca. 1 mm long, adnate to 5-6 mm above the base of corolla tube, glabrous. Disc annular, ca. 1 mm high, margin undulate, glabrous, white. Pistil pale green, 2.8-3.2 cm long; style linear, 1.9-2.3 cm long, ca. 1 mm in diam., upper part densely glandular-puberulent, lower part densely glandular-puberulent and eglandular-puberulent, ovary oblong, ca. 10 mm long, ca. 2 mm in diam., densely villous and glandular-pubescent, parietal placenta. Stigma acute triangle to narrowly obtrapeziform, 2-lobed, ca. 3 mm long. Capsule linear, 2-4 cm long, parietal placenta, densely villous and glandular-pubescent.

Phenology.

Flowering from April to May, fruiting from June to September.

Etymology.

The specific epithet ' jiulianshanensis ' is derived from the type locality, Jiulianshan National Natural Reserve, Jiangxi Province, China.

Vernacular name.

九连山报春苣苔 (Chinese name); Jǐu Lían Shān Bào Chūn Jù Tái (Chinese pronunciation).

Distribution and habitat.

We found three small subpopulations in Jiulianshan National Nature Reserve in Jiangxi Province, which are distributed in the shady and wet place on the cliffs under the evergreen broad-leaved forest in the reserve. And the new species is mainly acccompanied by Begonia palmata D.Don, Utricularia striatula J.Smith, Selaginella moellendorffii Hieron., S. involvens (Sw.) Spring, etc.

Conservation status.

At present, only three small subpopulations with total ca. 300 mature individuals of the new species are known in the type locality, Jiulianshan National Natural Reserve, Jiangxi Province, China. The three subpopulations are stable because they are in the reserve. The known AOO and EOO of the new species are about 0.2 km2 and 25 m2, respectively. Thus, if considering its fewer individuals of three subpopulations, it should be temporarily assessed as Near Threated (NT), following the IUCN Red List Categories and Criteria ( IUCN Standards and petitions committee 2022).

Notes.

The mainly morphological differences are showed in diagnosis and Table 3 . In addition, the insides of the corolla tube are also somewhat different. For example, at the junction of the abaxial and adaxial lip, there are two narrow triangular thickened dark reddish-brown stripes inside the corolla tube in Primulina jiulianshanensis , but there are only two bluish purple spots at the same places in P. wenii ; at corolla tube abdomen of P. jiulianshanensis , the upper parts of the longitudinal ridges are dark bluish purple, and the lower parts are yellowish brown, but the longitudinal ridges inside corolla tube of P. wenii are all dark bluish purple; the lump on the upper throat inside corolla tube of P. jiulianshanensis is dark reddish-brown, but P. wenii is dark bluish brown( Li et al. 2017).

The type locality of Primulina wenii is Rixi Township, Fuzhou, Fujian Province, while the type locality of P. jiulianshanensis is Jiulian Mountain, Jiangxi Province. Their type localities are separated by the Wuyi Mountains, and the two places are more than 500 kilometers apart. P. wenii has a narrow distribution range and is only recorded in Rixi Township, Fuzhou, Fujian Province ( Li et al. 2017). This area is coastal and the climate zone of this region belongs to the typical subtropical marine monsoon climate. P. wenii grows in the limestone evergreen broad-leaved forest area with stable morphology. P. jiulianshanensis , grows on the rocks under the evergreen broad-leaved forest in Jiulianshan Nature Reserve, which is a typical Danxia landform. The soil forming rock are mainly sandstone and conglomerate in Jiulianshan Nature Reserve, which has a subtropical monsoon humid climate. The morphology of the P. jiulianshanensis in three subpopulations is also relatively stable. Therefore, considering the differences in molecular, morphological, and habitats between P. jiulianshanensis and P. wenii , they should be classified as two different species.

Except for a few species, such as Primulina fimbrisepala (Hand.-Mazz.) Yin Z.Wang, P. eburnea (Hance)Yin Z.Wang, P. tenuituba (W.T.Wang) Yin Z.Wang, P. juliae (Hance) Mich. Möller & A.Weber, most of the species of Primulina are narrowly distributed and endemic. Among the known species worldwide, more than 170 species are endemic to Karst areas in southern to southwestern China and to northern Vietnam ( Wei 2018; Xu et al. 2020b). However, the diversity of Primulina in the Danxia landform has not been well understood so far ( Yu et al. 2019). For example, the new species, P. suichuanensis , was found in the Danxia landform in Jiangxi Province ( Zhou et al. 2016). It should be noted that a new provincial record for Primulina wenii from Jiangxi Province was discovered in Jiulianshan Nature Reserve ( Liao et al. 2020). However, we carefully examined the voucher specimen (No. PVHJX-05557, stored in GNNU), and we noted that the voucher was collected from the same subpopulation of P. jiulianshanensis from the same site in Jiulianshan Nature Reserve. Further, we found there are many inconsistencies between the morphological description from the article ( Liao et al. 2020) and the corresponding voucher specimens. Thus, this species’ new provincial record of P. wenii in Jiangxi province is a mistaken identification. Lastly, none of the close relatives of Primulina are morphologically similar to this new species found in Jiangxi (Fig. 1 ). Thus, the new taxon is not easily confused with the others in this province.

Figures

Figure 1. Phylogenetic tree of Primulina generated from maximum likelihood (ML) of combined trn L-F and ITS data-set. Numbers of each branch are support values in the order of UFBoot / BIPP. Stars indicate UFBoot = 100 % or BIPP = 1.0. The dash (-) indicates a node with UFBoot or <50 % or BIPP <0.5.

Figure 2. Primulina jiulianshanensis sp. nov. A habitat B population C plant in blooming D habit E adaxial surface of mature leaf blades and petiole F abaxial surface of mature leaf blade and petiole.

Figure 3. Primulina jiulianshanensis sp. nov. A cyme B adaxial surfaces of bracts C abaxial surfaces of bracts D adaxial surfaces of calyx lobes E abaxial surfaces of calyx lobes F opened corolla G stamens and anthers H one of lateral staminodes I pistil J immature capsules K transverse section of capsule.