Epimedium daiguii C. Zhang, B.L. Guo & Q.R. Liu, 2024

Zhang, Cheng, Liu, Xiang, Nie, Ze-Long, Meng, Ying, Guo, Bao-Lin & Liu, Quan-Ru, 2024, Epimedium daiguii (Berberidaceae), a new species from central China, Phytotaxa 634 (1), pp. 79-84 : 80-82

Epimedium daiguii C. Zhang, B.L. Guo & Q.R. Liu , sp. nov. ( Figures 1 & 2 ).

Diagnosis: This new species is most similar to E. elachyphyllum . However, the long stout rhizomes, two opposite cauline leaves, three leaflets, and paniculate inflorescences of this new species can be distinguished from E. elachyphyllum with elongate rhizomes, a single cauline leaf, one leaflet and simple inflorescences ( Table 1).

Type:— China, Hunan Province, Longshan County, Liye Town, Bamianshan Mountain, alt. 1299 m, 10 April

2017, C. Zhang Zhang214 (holotype BNU).

Perennial herbs 15–35 cm high. Rhizomes stout, fibrous roots numerous. Leaves basal and cauline, with 3 leaflets; leaflets ovate, 3.7–8.2 × 2.4–4.1 cm; apices short acuminate; bases cordate, terminal leaflets with equal and rounded, lateral leaflets conspicuously oblique with inner lobes small, rounded or acute, outer lobes larger, rounded, acute, or acuminate; margins spiny-serrate; leathery, the adaxially glabrous, abaxially glabrous or sparsely puberulent, often pruinose. Flowering stems 15–35 cm tall, with two opposite leaves. Inflorescence compound, 5–16 cm tall, with 23–50 flowers, glabrous, pedicels 1–2 cm. Flowers small, 8–12 mm in diam. Outer sepals dark violet, unequal in length, one pair ca. 2 mm, other pair ca. 3 mm, soon falling; inner sepals reddish, ovate, 3–5 × 1.6–2.6 mm, apices acute. Petals much shorter than inner sepals, reddish-purple, spur short 1.7–2.5 mm long, laminae yellow ca. 1 mm. Stamens yellow, ca. 2.5 mm long; anthers ca. 1.8 mm long. Capsule ca. 2.2 cm long, seeds brown, ca. 3.5 mm.

Etymology: —The new species is named in honor of Mr. Dai-Gui Zhang from the College of Biology and Environmental Sciences, Jishou University, Hunan, China. He has made great contributions to a better understanding of the plant diversity in the Wuling Mountains region.

Distribution and habitat: — E. daiguii is found only from its type locality, Bamianshan mountain, Liye town, Longshan County, Hunan Province, China. It grows in shrubs on hills at elevations of 1250–1390 m with associated plants, e.g., Pteridium aquilinum var. latiusculum , Ilex pernyi , Spiraea japonica , Rubus buergeri , Miscanthus floridulus and Hosta ventricosa .

Phenology: — E. daiguii flowers between April and May, and fruits in May.

Additional specimens examined: — China, Hunan Province, Longshan County, Liye Town, Bamianshan Mountain : 22 April 2012, Y. Xiao & J. J. Zhou LS-001 ( CSH!) ; 24 May 2013, Y. Xiao, D. K. Tian, C. Li & C. Zhang LS-1918 ( CSH!) .

IUCN Red List category: —During our botanical exploration in Hunan, Hubei, Guizhou, and Chongqing from 2016 to 2021, we found that Epimedium daiguii only occurs in its type locality. The vegetation around the holotype was disturbed by human activities such as tourism, pasturage and building roads. According to IUCN Red List Criteria ( IUCN 2001), E. daiguii should be considered vulnerable (VU D2).

Affinities: — Epimedium sect. Diphyllon allies display remarkable morphology, such as flowers size (range from 6 to 50 mm), inflorescence types (simple raceme, or compound raceme), and leaf morphology (simple, trifoliolate, biternate or pinnate) among other traits. Epimedium sect. Diphyllon ser. Brachycerae Stearn (1938: 500) species are characterized by distinct small flowers whose petals are very short (much shorter than inner sepals), usually only 1–4 mm long. In the past, 12 Chinese Epimedium species have been recognized into the series ( He et al. 2010; Stearn 2002; Wang et al. 2017; Zhang 2023). E. daiguii , the new species, shares common traits of ser. Brachycera should be sorted into this series.

E. daiguii is closely distributed with E. elachyphyllum . E. elachyphyllum is locally distributed in the hill of Songtao, Guizhou Province, and E. daiguii only occurs in Bamianshan Mountain, Hunan Province. The divergence of these two species probably was facilitated by the isolation of gap between the two mountains. Further studies with other molecular and genetic evidence are needed to make a clear understanding on the speciation of these two closely related species.

Figures

FIGURE 1. Living images of Epimedium daiguii. A. Habit. B. Inflorescences and leaves, C–D. Flower. E. Rhizome.

FIGURE 2. Illustration of Epimedium daiguii. A. Whole plant. B–C. Flower. D–E. The longer outer sepal (D) and the short outer sepal (E). F. Inner sepal. G. Stamen. H. Gynoecium. Drawn from the holotype (C. Zhang Zhang214) by Q.R. Liu.