Primulina quanzhouensis F.Wen, J.X.Fu & B.Pan, 2025

Primulina quanzhouensis F.Wen, J.X.Fu & B.Pan , sp. nov. ( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 , 4 View FIGURE 4 AB)

Type: — CHINA. Guangxi Zhuangzu Autonomous Region: Guilin City, Quanzhou County, Jiaojiang Town, Mopan reservoir, 23°35'5.37″N, 110°50'16.46″E, alt. ca. 360 m, growing on the top of a cliff on a limestone hill along the road, 28 March 2020, Fang Wen WF200328- 01 ( holotype: IBK 00470685!, isotype: IBK 00470686!).

Diagnosis: —Morphologically, Primulina quanzhouensis resembles P. yungfuensis ( Wang 1987: 125) Mich.Möller & A.Weber in Weber et al. (2011: 785), but it is distinguished from the latter by its leaves nearly rounded to slightly oblate ( vs. leaves oval, ovate or nearly orbicular), cymes unbranched or 1-branched, usually 2-flowered or sometimes more ( vs. cymes usually 2–branched, 4–10-flowered) and bracts elliptic ( vs. bracts ovate to nearly rhombus or broadly cymbiform).

Description: —Perennial herbs, accaulescent. Rhizomes subterete to conical, usually small, 5–8 mm long, 3–5 mm in diameter. Leaves 6–8, basal, opposite, inconspicuously petiolate when mature, nearly sessile when young; petiole pale green, flattened, cross-section fusiform but often slightly obtuse at both ends, (0–)1–4 × (0–)0.6–1.0 cm, very sparsely pubescent to nearly glabrous; leaf blade dark green to slightly purplish green or slightly brownish green, thick herbaceous to slightly fleshy, nearly rounded to slightly oblate, 3.5–6.5 × 4–7 cm, apex obtuse to nearly rounded, base broadly cuneate, eudipleural, margin entire and sometimes slightly revolute, densely vertically pubescent on both surfaces; 3–4 pairs of lateral veins on each side of the midrib; adaxially main vein and lateral conspicuously sunken, abaxially main vein and lateral vein conspicuously raised. Cymes 1–4, axillary, unbranched or 1-branched, usually 2-flowered or sometimes more; peduncles pale brownish purple to pale purple, 5–6.5 cm long, 1.5–2 mm in diameter, brownish purple to purple pubescent; bracts 2, opposite, both surfaces green and the bottom brownish purple, elliptic, 9–12 × 4–6 mm, brownish purple pubescent abaxially and glabrous adaxially; pedicels greenish brown, 2–3 cm long, 1–1.5 mm in diameter, white to pale brownish puberulent. Calyx 5-lobed from the base, lobes obovate, apex acute, margin denticulate 2–3 on each side from the apex downward to ca. 1/3 of its length, 10–12 × 2.5–3.2 mm, outside sparsely pubescent, inside nearly glabrous. Corolla lilac to purple, tube outside lilac to purple and inside gray white to white but suffused with a pale purplish hue, all lobes lilac to purple, two upper lip lobes each bearing two slightly raised maroon patches at their point of juncture, patches somewhat connected at the top, diverging below and extending to 1/4 to 1/3 the total length of the corolla tube, the connected places of limb upper lip lobe and lower lip lateral lobes with a pale brownish-red patch, each lower limb lobes with 1–2 dark purple longitudinal stripes extending down to 1/3 to 1/2 the total length of the corolla tube, 2 longitudinal yellow nectar guides (ca. 5 mm long) presented at the bases of the lower lip lobes where the two lateral lobes connect with the central lobe, extending inward towards ca. 2/3 the total length of the corolla tube; zygomorphic, 5–6 cm long, outside white puberulent mixed fewer glandular-puberulent, inside glabrous; tube funnelform-tubular, 1.3–1.6 cm long, 1.3–1.5 cm in diameter at the mouth, ca. 5 mm in diameter at the base; limb distinctly 2-lipped; adaxial lip 2-lobed to nearly the base, lobes nearly obvoate, 1.3–1.5 cm long, 1.2–1.4 cm wide at the base, apex suborbicular; abaxial lip 3-lobed to the base, lobes elliptic, 1.6–1.8 mm long. Stamens 2, adnate to 10–12 mm above the corolla base; filaments sparsely glandular-puberulent, white, 12–14 mm long, slightly geniculate at 1/3 from the base upward to the top; anthers purple, 5–5.5 mm long, fused from the entire adaxial surface, barbate; staminode 3, lateral ones obvious, white, linear, glabrous, 5–6 mm long, adnate to ca. 12 mm above the corolla base; the center 1, clavate, ca. 2 mm long, adnate to ca. 7 mm above the corolla base. Disc annular, slightly oblique, ca. 1.6 mm high at the higher part and ca. 1 mm high at the lower part, margin repand. Pistil 3–3.2 cm long; ovary yellowish green to brownish green, parietal placentation, ca. 2.5 cm long, densely white pubescent interspersed few glandular-pubescent; style white, ca. 6 mm long, puberulent in the lower half, with the puberulent gradually becoming shorter and sparser from the middle towards the stigma, eventually becoming nearly glabrous in the upper half; stigma trapeziform, ca. 3 mm long, apex slightly 2-lobed to 1/3 of its length, lobes ligulate, ca. 0.8 mm long. Capsule narrowly linear, 5–6 cm long, ca. 2.5 mm in diameter, straight, dehiscing loculicidally into two valves when mature and dry.

Phenology: —Flowering from March to the first half of April, fruiting from June to July.

Etymology: —The specific epithet is derived from the type locality, Quanzhou County.

Vernacular name: —Quán Zhōu Bào Chūn Jù Tái (Chinese pronunciation); Ìfflǟfffiă (Chinese name).

Distribution and habitat: —Quanzhou County has a subtropical humid monsoon climate, characterized by mild temperatures, abundant rainfall, and distinct seasons. The long-term average annual temperature is 17.7°C, and the long-term average annual rainfall is 1,492.2 mm. All rivers within the county belong to the Xiangjiang river system of the Yangtze River basin. Quanzhou County boasts a rich karst landform landscape, featuring typical subtropical karst landform features such as stone buds, stone forests, caves, sinkholes, poljes, and trough valleys. Primulina quanzhouensis is found exclusively at its type locality, which is situated on a limestone cliff at the foot of a mountain near a reservoir in Jiaojiang Town, Quanzhou County, at an elevation of approximately 360 meters. Due to significant seasonal rainfall, the rock surface where this species grows remains moist or even saturated with dripping water for over four months during the spring and summer rainy seasons. In contrast, the area experiences a dry period lasting more than three months during autumn and winter. The growth site is on a near-vertical, north-facing rock face, resulting in very few associated plants, with only a small number of Poaceae species present. At the top of cliff, perennial evergreen shrubs provide shade and shelter.

Preliminary conservation assessment: —Quanzhou County is located in the northeastern part of Guilin City, in the upper reaches of the Xiangjiang River, and is known as the "North Gate of Guangxi ". Quanzhou County has a subtropical monsoon climate. The type locality of this new species is located beside the county road near Mopan Reservoir in Jiaojiang Town. The reservoir is surrounded by limestone hills, with various shady and humid cliffs, depressions, and caves suitable for the growth of species of Primulina . The site of the initial discovery was a cliffside by the road. According to statistics, this site densely distributed about 400 adult individuals. However, the road expansion around 2022 directly destroyed and wiped out this site. Multiple field expeditions in 2023 and 2024 found that the number of individuals of this species has dropped sharply from more than 400 to less than 10 mature individuals, with no juvenile plants for renewal. In the spring of 2025, by a chance, a population of this species was discovered again on another isolated limestone peak about 5 km away from the first discovery site in a straight line, with about 100 mature individuals. Since a large number of dead individuals can be clearly observed in the population of the new distribution site, this may be caused by the continuous severe drought in the second half of 2024. It is preliminarily estimated that the number of individuals in this newly discovered population has decreased by 40% or more. We still need to conduct more in-depth surveys of the habitat to find any possible populations. For this current study, we temporarily assess the status of this species as Critically Endangered. Following the IUCN Red List Categories and Criteria ( IUCN Standards and Petitions Committee, 2024), this new species is provisionally evaluated as Critically Endangered [CR B2ab(V)].

Notes: —Beyond its morphological similarities to Primulina yungfuensis , the new species, P. quanzhouensis , also bears a resemblance to P. yangshuoensis Wen & Wei (2012: 56) . However, P. quanzhouensis can be distinguished by the following characteristics: fewer cyme per plant numbering 1–4 ( vs. 8–10), larger elliptic bracts 9–12 × 4–6 mm ( vs. lanceolate or subulate, 1–2 × 0.3–0.5 mm), larger flowers 5–6 cm long and externally puberulent with sparse glandularpuberulence ( vs. 2–3 cm long, externally puberulent), filaments sparsely glandular-puberulent ( vs. glabrous). While P. quanzhouensis and P. yungfuensis share a similar flowering period (both in spring), their distribution areas do not overlap, indicating geographic isolation. In contrast, P. yangshuoensis flowers in autumn, demonstrating clear temporal reproductive isolation from both P. quanzhouensis and P. yungfuensis . To confirm the new species' independence, we conducted a four-year common garden experiment involving all three species. The results consistently showed that the distinguishing characteristics of P. quanzhouensis remained highly stable under cultivation, exhibiting no convergence with the other two species. This strongly supports its genetic distinctiveness.Additional key morphological distinctions between P. quanzhouensis and the other two species can be found in Table 1 and Fig.4 View FIGURE 4 . Ultimately, both qualitative and quantitative trait differences robustly support the validity of this new species.