Prunus zhuxiensis Q. L. Gan, W. B. Xu & X. W. Li, 2025

Prunus zhuxiensis Q. L. Gan, W. B. Xu & X. W. Li sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3

Diagnosis.

Prunus zhuxiensis is similar to P. serrulata Lindl. ( Li and Bartholomew 2003; Yi et al. 2024 b) in its hairy pedicel and involucral bracts, corymbose-racemose or subumbellate inflorescences and black drupes, but the flowers of P. zhuxiensis appear before the leaves (at the same time as leaves in P. serrulata ) and have reflexed sepals half as long as the hypanthium (spreading sepals up to as long as hypanthium in P. serrulata ) and style pilose at the base (glabrous in P. serrulata ), the fruits of P. zhuxiensis are sweet and edible, while those of P. serrulata bitter and inedible.

Type.

China • Hubei Province, Zhuxi County, Quanxi Town, Baguashan Forest Farm, Hengduanshan , 32°3'50"N, 109°39'25"E, alt. 780 m, 15 March 2023, Q. L. Gan 23-1 - 1 (holotype: HIB [barcode 0342513!]; Isotypes, PE [barcodes 02553525!, 02553526!]) GoogleMaps .

Paratypes: • ibidem, alt. 780 m, 15 March 2023, Q. L. Gan 23-1 - 2 ( HIB [barcode 0346560!]), Q. L. Gan 23-1 - 3 ( HIB [barcode 0346559!]), Q. L. Gan 23-1 - 4 ( HIB [barcode 0346563!]) GoogleMaps ; • ibidem, alt. 750 m, 26 April 2023, Q. L. Gan 23-2 - 1 ( HIB [barcode 0346561!]), Q. L. Gan 23-2 - 2 ( HIB [barcode 0346562!]), Q. L. Gan 23-2 - 3 ( HIB [barcode 0346564!]) GoogleMaps .

Description.

Trees, deciduous, 8–12 m tall, bark grey, lenticels elliptic or long elliptic, sparsely transversely arranged. Young branchlets purple or green, densely grey pubescent. Leaf blades narrowly obovate, obovate or elliptic, 3–12 × 1.5–5.5 cm, base cuneate or rounded, apex caudate or acuminate, margin crenately serrate or biserrate, teeth minute, tipped with apical glands, adaxially glabrous, abaxially white pilose on veins. Secondary veins 8–12 on each side. Petiole 10–14 mm, pubescent, with two purple disciform glands at upper part. Stipules 4 - lobed at base, lobes margin capitate gland tipped, laciniato-fimbriate. Flowers emerging before leaves. Involucral bracts ovate, oblong, 4–7 × 3.5–4.5 mm, densely pubescent adaxially. Inflorescences umbellate or corymbose-racemose, 3–5 - flowered. Peduncles short or absent. Pedicel 7–12 mm, pubescent. Bracts greenish-white, obovate, 1.5–2.5 × 1.5–2.5 mm, conical glandular serrate at apex. Hypanthium tabulate or campanulate, 6–7 × 2–3 mm, pubescent abaxially. Sepals ovate-lanceolate, 2–3 × 0.8–1 mm, reflexed. Styles 12–13 mm, pilose at base. Petals ovate or narrowly ovate, white, 10–13 × 6–7 mm, bifid at apex. Stamens 38–44, filaments up to 12 mm. Drupes globose or ovoid, black, 8–9 mm long, sweet, edible. Endocarp flat ovoid, 7–8 mm long, smooth.

Phenology.

Flowering in March, fruiting in May.

Distribution and habitat.

P. zhuxiensis is distributed sparsely in the mixed evergreen and deciduous broad-leaved forest in the mountains or along streams at altitudes 600–1500 m around the type locality. The main accompanying species of P. zhuxiensis are Salix wilsonii Seemen ex Diels , Sycopsis sinensis Oliv. , Camellia cuspidata (Kochs) H. J. Veitch , Phoebe zhennan S. K. Lee & F. N. Wei , Juglans mandshurica Maxim. , Albizia julibrissin Durazz. , Pterocarya stenoptera C. DC. , Cornus kousa subsp. chinensis (Osborn) Q. Y. Xiang , Photinia beauverdiana C. K. Schneid etc.

Etymology.

The specific epithet “ zhuxiensis ” refers to the type locality, Zhuxi, Hubei, China. The Chinese name of this species is Zhuxiyingtao (Pinyin).

Notes.

P. zhuxiensis co-occurs with P. serrulata in the same plant community. They are similar in their hairy pedicel and involucral bracts and black drupes. However, these two species can be distinguished by the pilose style base of P. zhuxiensis (which is glabrous in P. serrulata ) and the sweet and edible drupes of P. zhuxiensis (compared to the bitter and inedible drupes of P. serrulata ). The morphological differences are shown in Table 1 View Table 1 , Suppl. material 1.

Molecular phylogeny.

Both the BI and ML molecular trees (Fig. 4 View Figure 4 , Suppl. material 2) demonstrate the monophyly of Prunus subg. Cerasus , which is consistent with Shen et al. (2023). Shen et al. (2023) split the subg. Cerasus into seven lineages (Clades IIIa – IIIg) and the species of each of these lineages also cluster together in our phylogenetic trees. The new species P. zhuxiensis does not group with P. serrulata and it is nested in clade IIIc of Shen et al. (2023) and sister to a subclade consisting of P. dolichadenia Cardot , P. tatsienensis Batalin , P. szechuanica Batalin , P. discadenia Koehne , P. conadenia Koehne , P. serrula Franch. and P. pleiocerasus Koehne. P. serrulata and P. serrulata var. lannesiana (Carrière) Makino and P. sargentii Rehder group together into a subclade as a part of clade IIIg of Shen et al. (2023). The present study shows that phylogenetic relatedness does not reflect the morphological resemblance of P. zhuxiensis and P. serrulata . While both P. zhuxiensis and P. subhirtella are placed in the same clade named IIIc of Shen et al. (2023), these two species share the characters of black drupes and hairy inflorescences and pilose style.

Key to species of Prunus subg. Cerasus in Zhuxi, Hubei, China (based on Li and Bartholomew (2003 ))