Diospyros adinandrifolia Y.M. Shui, Z.X. Zhang & C.Y. Zou

Liu, Qun, Zou, Chun-Yu, Yang, Chong, Chen, Wen-Hong, Lyu, Ling, Zhang, Gui-Liang, Shui, Yu-Min & Zhang, Zhi-Xiang, 2024, Diospyros adinandrifolia, a new species of Ebenaceae from Yunnan, China, Phytotaxa 649 (1), pp. 121-129 : 122-127

Diospyros adinandrifolia Y.M. Shui, Z.X. Zhang & C.Y. Zou sp. nov. ( Figs. 1–5 )

Type: — CHINA. Yunnan: Hekou County, Nanxi Town, Longbao Village , elevation 750 m, in the tropical rainy forest along the limestone valley, 10 April 2023, female flowers, C. Y. Zou, J. Q. Huang & Z. C. Fan ZCY4316 (holotype: IBK!; isotype: KUN!) .

Diagnosis: —The new species resembles Diospyros undulata Wall. ex G. Don (1838: 40) and D. dussaudii Lecomte (1928: 113) . It is similar to D. undulata in its elliptic leaves, clustered flowers, and synsepalous calyces, but differs in its abaxial leaf base without glands (vs. with a pair of glands), calyx lobes being absent or less than 1/10 as long as the whole calyx (vs. approximately 1/3–1/2 as long as the calyx), fruiting calyx lobes being not reflexed and almost not wrapping the base of fruit (vs. reflexed and wrapping up to 1/2 of fruit), and its fruit being 4–5 cm (vs. 1.5–2.6 cm) in diameter. It is also similar to D. dussaudii Lecomte in having similar buds and flowers, but differs in its leaves being white pubescent when young and glabrescent (vs. densely ochre brown villous), racemose (vs. fasciculate) male inflorescences, and succulent (vs. xyloid) fruit ( Table 1 ).

Evergreen plants, dioecious. Tree to 20 m tall, trunk to 71 cm in diameter at breast height (DBH); bark grey, densely lenticellate. Young branchlets green. Twigs with appressed whitish pubescence when young, becoming glabrous with age. Buds covered by bifarious scales. Leaves leather, lanceolate or elliptic-lanceolate, 6.0– 18.5 cm long, 2.0–6.0 cm wide, apex acute or acuminate, base cuneate or broadly cuneate, mid-rib adaxially impressed, mid-rib abaxially prominent, white pubescent when young; lateral veins pinnate, 7–10 pairs, slender; veinlets obviously reticulate; Petiole 0.6–1.3 cm, white pubescent; buds brown pubescent. Flower buds ovoid, with bifarious scales at base, scales 3–6, broadly ovate, brown strigose, deciduous after flowering. Male inflorescences racemose, 2–4 cm long, each bearing 3–6 flowers. Male flowers 4(–3)-merous, calyx cylindrical, with 4(–3) short triangular lobes, 5–7 mm, densely covered with long white hairs; corolla pale yellow, urceolate, pubescent outside, glabrous inside, lobes ovateorbicular, reflexed; stamens 16, arranged in 2 series, attached at the base of corolla tube; anthers triangular, 4.0–6.0 × 1.5–3.0 mm, apex apiculate, white pubescent; rudimentary ovary densely pubescent. Female inflorescences consisting of a solitary flower on a ca. 0.2 cm long stalk. Female flowers 4(–3)-merous, calyx tubular, margin emarginate; corolla pale yellow, urceolate, lobes ovoid, reflexed, densely pubescent outside, glabrous inside; Staminodes 8, attached at the base of corolla tube, filaments flattened, anthers triangular; ovary globose, densely white pubescent, 8-locular; stigmas 4. Fruit succulent, globose or depressed-globose, angular-sulcate, 3.5–5.8 cm in diam., covered with silvery-grey hairs; persistent calyx leathery, 1.5–2.0 cm in diameter, outside densely silvery-white hairs, inside nearly glabrous; fruiting stalk stout, ca. 1.0 cm long, densely silvery-white hairs; light green when immature, turning yellow and orange when ripe, with 2–8 seeds; Seeds dark brown, triangular-oblong, compressed, 2.5–3.2 cm long, 1.5–2.0 cm wide.

Phenology & ecology: —Flowering April, fruiting from May to August.

Etymology: —The specific epithet is due to the leaf shape and texture resembling those of the genus Adinandra Jack (1822: 49) in Theaceae . The Chinese name for this species is: 杨桐柿.

Habitat & distribution: —At present, this species has been discovered in the permanent monitoring plot of tropical rainforest in the Gulinqing Natural Reserve of Maguan County and Hekou County, southeast Yunnan, where the topography is a typical karst depression, and the habitat is relatively fragile and fragmented due to nearby farming. It is scattered in the tropical rainy forests at elevations of 530–800 m, mainly composed of species such as Caryodaphnopsis tonkinensi s ( Lecomte 1913: 106) Airy Shaw (1940: 74), Pometia pinnata Forster & Forster (1776: 110) , Phrynium rheedei Suresh & Nicolson (1986: 355) .

Additional specimens examined (paratypes): — CHINA. Yunnan: Hekou County, Nanxi Town , elevation 800 m, 11 April 2023, male flowers, C.Y. Zou, J.Q. Huang & Z.C. Fan ZCY4320 ( IBK, KUN, IBSC) ; Maguan County, Gulinqing Community, Bojia Village , the 25-ha permanent monitoring plot of the tropical rain forest, elevation 530– 610 m, 22°42’58”N, 103°53’42”E, 4 September 2023, Yu-Min Shui et al. GLQ0204-106 ( KUN) .

Conservation status: —At present, this species is known in two localities in Yunnan with a total of less than 69 mature individuals. Some individuals discovered occur within the range of reserves, where the habitats are in good condition. A small number of individuals are disturbed by agricultural activities. The localities are close to Vietnam, possibly expanding to North Vietnam. According to IUCN Standards and Petitions Subcommittee (2022), this new species should be regarded as Endangered (EN).

Figures

FIGURE 1. Diospyros adinandrifolia, sp. nov. A. Habit. B. Trunk and bark. C. Female flowering twigs. D. Male flowering twigs. E. Young twig. F. Female inflorescences. G. Male inflorescences. (from C.Y. Zou, J.Q. Huang & Z.C. Fan ZCY4320; photos by Chun-Yu Zou & Gui-Liang Zhang).

FIGURE 2. Diospyros adinandrifolia,sp.nov. A. Leaves, adaxial surface.B. Leaves,abaxial surface.C–E. Femaleflowers.F. Longitudinal section of male flower. G–I. Male flowers. J. Calyx of male flowers. K. Top view of male flowers. L. Top view of female flower. M. Longitudinal section of female flower. N. Young fruit. O. Immature fruit. P. Ripening fruit. Q. Longitudinal section of fruit. R. Seeds. (from holotype, C.Y. Zou, J.Q. Huang & Z.C. Fan ZCY4316; photos by Chun-Yu Zou & Gui-Liang Zhang).

FIGURE 3. Diospyros adinandrifolia, sp. nov. A. Flowering branch. B. Female inflorescences. C. Male inflorescences. D. Mature leaves. E. Young leaves. F. Part of dried leaves, abaxial surface. G. Part of dried leaves, adaxial surface. H. Fruiting branch. I. Fruit, bottom oblique view showing the fruiting calyx. J. Fallen fruits on the ground. K. Mature fruit. L. Mature seeds. (from Yu-Min Shui et al. GLQ0204-106, A, B, H, and I were photographed by Y.M. Shui; all others were photographed by Ling Lyu)

FIGURE 4. Diospyros adinandrifolia, sp. nov. A. Male flowers. B. Longitudinal section of male flower, showing stamens. C. Stamens. D. Female flowers. E. Longitudinal section of female flower, showing ovary. F. Opened corolla of female flower, showing staminodes. G. Pistil. H. Pistil, top view, showing stigmas; I. Lateral view of pistil; J. Transverse ovary showing eight ovules. (from Yu-Min Shui et al. GLQ0204-106, all photographs taken by Ling Lyu)

FIGURE 5. A. A. Holotype of Diospyros adinandrifolia, sp. nov. (♀): C.Y. Zou, J.Q. Huang & Z.C. Fan ZCY4316 (IBK417309); B. Paratype of Diospyros adinandrifolia, sp. nov. (♂): C.Y. Zou, J.Q. Huang & Z.C. Fan ZCY4320 (IBK417307).

Tables

TABLE 1. Morphological comparison among Diospyros adinandrifolia, D. undulata, and D. dussaudii.

Morphological characters	D. adinandrifolia	D. undulata	D. dussaudii
Bifarious scales covering the bud	Present	Absent	Present
Leaves	Abaxially without glands at the leaf base	Abaxially with a pair of glands at the leaf base	Abaxially without glands at the leaf base
Male inflorescences	Racemose, 2.0–4.0 cm long	Racemose, 5.0–7.0 mm long	Fasciculate
Flower calyx	Cylindrical, with 4 short triangular lobes, lobes ca. 1 mm long	Campanulate, divided to middle, lobes ca. 4.0–5.0 mm long	Tubular, with 4 short lobes, lobes ca. 5.0 long
Fruiting calyx lobes	Spreading	Erect	Spreading
Fruit size	3.5–5.8 cm in diameter	1.5–2.6 cm in diameter	4.0–5.0 cm in diameter