Beilschmiedia weii Y.S. Huang, H.M. Tan & Yan Liu, 2022

Huang, Yu-Song, Qin, Kun, Tan, Hai-Ming, Zou, Chun-Yu & Liu, Yan, 2022, Beilschmiedia weii (Lauraceae), a new species from Dayaoshan Mountain of Guangxi, China, Phytotaxa 564 (1), pp. 127-132 : 128-131

Beilschmiedia weii Y.S. Huang, H.M. Tan & Yan Liu , sp. nov. ( Figure 1 )

Type: — CHINA. Guangxi Zhuang Autonomous Region: Laibin City , Jinxiu Yao Autonomous County, roadside from Jichong Village of Luoxiang Town to Gucheng Village of Liuxiang Town. elev. 866 m, 16 May 2021, Y.S. Huang & C.Y. Zou Y2021051601 (holotype: IBK!, isotypes: IBK!, GXMG!) .

Diagnosis: —The new species is morphologically similar to Beilschmiedia wangii and B. rufohirtella in having ferruginous pubescent terminal buds, branchlets, abaxial leaf blades, panicles and fruiting pedicels, but can be distinguished from the former by leaves alternate or subopposite (vs. opposite), adaxial leaf blade densely ferruginous pubescent when young, glabrescent except midrib (vs. glabrous), flowers yellowish green (vs. white), lateral veins 10–13 pairs (vs. 8–9 pairs), panicles 4.5–16 cm long (vs. 4–8 cm), fruits ellipsoid, 2–2.5 × 1.5–2 cm (vs. narrowly ellipsoid, ca. 5.5 × 2.2 cm), fruiting pedicels not incrassate, 2–3 mm long (vs. incrassate, up to 2.5 cm), and from the latter by panicles 4.5–16 cm long (vs. 1.8–3 cm), fruits ellipsoid, 2–2.5 × 1.5–2 cm (vs. ellipsoid-oblong, 4.5–5.5 × 2.5–2.7 cm), fruiting pedicels not incrassate, 2–3 mm long (vs. incrassate, ca. 5 mm).

Trees, up to 20 m tall, 0.6 m in DBH (diam. at breast height). Bark brownish gray. Branchlets 2–3 mm in diam., grayish brown or green, densely ferruginous pubescent when young, sparsely ferruginous pubescent when old, and blackish brown when dry. Terminal buds narrowly ovoid, 6–10 mm long, densely ferruginous pubescent. Leaves alternate or subopposite; leaf blades lanceolate, broadly lanceolate to elliptic-lanceolate, 6.5–15 × 2.5–6 cm, adaxially densely ferruginous pubescent when young, glabrescent except midrib, abaxially densely ferruginous pubescent, base broadly cuneate to obtuse, often oblique, apex acute, midrib adaxially impressed, abaxially elevated, densely ferruginous pubescent, lateral veins 10–13 pairs, adaxially plane or slightly elevated, densely ferruginous pubescent when young, glabrescent, abaxially elevated, minor veins abaxially slender, densely ferruginous pubescent, conspicuously faveolate when dry; petiole 1.5–2.5 cm long, densely ferruginous pubescent. Inflorescence paniculate; panicles axillary, 4.5–16 × 3–5.5 cm; rachis slightly robust, densely ferruginous pubescent; bracts caducous; flowers yellowish green, ca. 3 mm in length, 4–5 mm in diam.; pedicels 2–3 mm long, densely ferruginous pubescent; perianth lobes 6, ovate or broadly ovate, ca. 2 × 2.5 mm, densely ferruginous pubescent on both surfaces; fertile stamens 9 in three whorls, those of outer whorls opposite to perianth lobes, eglandular, subequal, 1–1.5 mm long, filaments short and densely pubescent; those of 3rd whorl each with 2 stalked or stalkless glands at base; anther cells of outer whorls introrse, those of 3rd whorl extrorse; the tip of anthers glabrous; staminodes of 4th whorl triangular, pubescent, ca. 0.8 mm long; pollen round, 25–30 μm in diam., surface with conical spines; ovary ovoid, ca. 1 mm in diam., glabrous; style ca. 1 mm long. Fruits ellipsoid, 2–2.5 × 1.5–2 cm, glabrous, black when mature, tuberculate when dry, subrotund at both ends; fruiting pedicels not incrassate, red-brown, 2–3 × 1–2 mm, ferruginous pubescent; seeds ellipsoid, testa glabrous, tuberculate.

Phenology: —The new species was observed flowering from April to May, and fruiting from July to August.

Etymology: —We dedicate this new species of Beilschmiedia to Prof. Fa-Nan Wei for his substantial contributions to taxonomic research of the family Lauraceae . Wei was one of the first persons to realize that Beilschmiedia weii would probably represent an undescribed species and provided the nomen nudum ‘ Beilschmiedia mollifolia X.L. Mo et F.N. Wei’ on annotation label of the Dayaoshan team 13913 (IBK00189612!) and the Dayaoshan team 12214 (IBK00189611!, IBSC 0044982!) specimens. Since the new species is endemic to Dayaoshan Mountain of Guangxi, China, we propose its vernacular name in Chinese as ‘ 大ẈƜDzff ’ (Chinese pinyin: dà yǎo shân qiǒng nǎn).

Distribution and habitat: — Beilschmiedia weii is currently found only from Dayaoshan Mountain of Guangxi, China ( Figure 2 ). It grows on the edge of valley in evergreen deciduous broad-leaved forests, with an elevation of ca. 860 m. The slope direction of the type locality is towards East, and its declivity is ca. 35°. The tree layer is up to 22 m tall with a canopy cover of 70%, and the shrub and herb layer cover are 60% and 70%, respectively.

Conservation status: — Beilschmiedia weii is so far only known in Dayaoshan mountain of Jinxiu County, Guangxi, China, and four subpopulations have been recorded from 1981 to 2021. Although wild investigations have been conducted in Dayaoshan mountain along more than ten years since 2010, just the subpopulation of type locality was found. The type locality is located in a protected area. However , this very small subpopulation is highly disturbed because it is located near a concrete roadside. The Extent of Occurrence (EOO) is ca. 320 km 2. The Area of Occupancy (AOO) known is 16 km 2. As a new species, however, fieldwork is still limited. It is likely that more subpopulations could be found in similar habitats in the future. According to current data and Guidelines for Using the IUCN Red List Categories and Criteria ( IUCN 2022), B. weii should be assessed as Endangered (EN) status based on the criteria B1ab(iii)+2ab(iii) ( IUCN 2012). How to preserve this species is our ongoing research task.

Additional specimens examined (paratypes): — CHINA. Guangxi Zhuang Autonomous Region: Jinxiu County, Liuxiang Town , Dadeng Village , Wuzhishan , 620 m elev., 30 October 1981, Dayaoshan team 12214 (IBK, IBSC); the same County, Jinxiu Town , Hekou, 810 m elev., 22 September 1981, Dayaoshan team 10997 (IBK, IBSC); the same County, Luoxiang Town , Huangzhuji of Luoxiang mountain, 490 m elev., 5 April 1982, Dayaoshan team 13913 (IBK); the same County, roadside from Jichong Village of Luoxiang Town to Gucheng Village of Liuxiang Town. elev. 866 m, 11 August 2014, Y.S. Huang & W.B. Xu Y2931 (IBK); the same location above, 31 July 2021, Y.S. Huang Y2021073102 (IBK) .

Discussion: Beilschmiedia weii is morphologically similar to B. wangii and B. rufohirtella , and their morphological comparison is summarized in Table 1 . It is a megaphanerophyte, which can reach a height of 20 meters. It is an upper layer tree and plays an important ecological role in the community. The specimens of the new species were first collected from Dayaoshan Mountain of Jinxiu County, Guangxi in 1981. However, specimens with flowers or fruits have not been collected since then. Despite the field surveys conducted many times in these recorded distribution points, we did not find any individuals of this new species. A different distribution point, i.e. the type locality, has not been found until 2014. It has also shown that this subpopulation is relatively limited, having only one adult individual. Although seedlings of this species have been found in the understory of the type locality, small trees have never been observed. It indicates that the natural regeneration of this species is relatively difficult, which may also be one of the reasons for its small population size. In addition, the type locality is placed on the edge of a protection zone, where anthropic interference hazards have not been banned. Furthermore, the adult individual of type locality grows next to a concrete road, which is the traffic thoroughfare of towns. Therefore, the habitat is threatened by destruction at any time, and the individuals are also in danger of being cut down. It is necessary to take protective measures to preserve the type locality and individuals.

Figures

FIGURE 1. Beilschmiedia weii Y.S. Huang, H.M. Tan & Yan Liu.A. Habitat; B. Habit; C. Tree trunk; D. Leaf blades; E. Fruiting branch; F. Mature fruits; G. Young fruits; H. Flowering branch; I. Part of inflorescence; J. Flower (showing the pubescent perianth lobes, fertile stamens and staminodes); K. Flower (lateral view); L. Tepals (dorsal view); M. Fruit (longitudinal view); N. Fruits (crosscutting view); O. Pollen (SEM micrograph, from Y.S. Huang & C.Y. Zou Y2021051601).

FIGURE 2. Distribution map of Beilschmiedia weii Y.S. Huang, H.M. Tan & Yan Liu.