Carpinus tibetana Z. Qiang Lu & J. Quan Liu, 2018

Lu, Zhiqiang, Li, Ying, Yang, Xiaoyue & Liu, Jianquan, 2018, Carpinus tibetana (Betulaceae), a new species from southeast Tibet, China, PhytoKeys 98, pp. 1-13 : 1

Carpinus tibetana Z. Qiang Lu & J. Quan Liu sp. nov. Figures 2 , 3

Diagnosis.

Carpinus tibetana differs from C. monbeigiana by 19-24 lateral veins on each side of the midvein and dense pubescence on the abaxial leaf and from C. mollicoma by the nutlet with dense resinous glands and glabrous or sparsely villous at apex.

Type.

CHINA. Tibet: Bomi County, Yigong, Tongmai , 95°04'31"E, 30°06'05"N, 2060 m, forest edge, 28 Aug 2016, Z.Q. Lu 2016QTP001 (holotype, LZU; isotypes, LZU, PE, KUN) .

Description.

Trees to 10 m tall, deciduous; bark grey, smooth. Branchlets dark grey, densely yellow or white pubescent when young, glabrescent the next year. Stipules deciduous. Petiole 5-8 mm, densely white or yellow puescent; leaves alternate, leaf blade ovate-elliptic or elliptic, usually 5-8 cm × 2-3 cm, abaxially sericeous-villous along veins, pubescent elsewhere, base rounded or rounded-cuneate, margin irregularly and doubly setiform mucronate serrate, apex attenuate-acuminate or caudate-acuminate; lateral veins (17) 19-23 on each side of midvein. Male inflorescence pendulous, spicate-cymose, cylindric, enclosed by buds during winter, with many overlapping bracts, 1.5-5.0 cm × 5.0-8.0 mm when mature; flowers without bracteoles, inserted at base of bracts. Female inflorescence terminal or axillary on dwarf shoots, racemose; flowers paired; bracts leaflike, complanate, overlapping. Mature infructescence 5-10 cm × 2.0-3.5 cm; peduncle ca. 1.2 cm, densely yellow hirsute; bracts of female flowers loosely overlapping, 1.5-1.9 cm × 6-8 mm, abaxially densely yellow hirsute along reticulate veins, outer margin coarsely dentate, without basal lobe, inner margin entire, with inflexed basal auricle, apex acuminate or caudate-acuminate; veins 5-6. Nutlet ovoid-ellipsoid, 3.2-3.6 mm × 2.2-2.5 mm, glabrous or sparsely villous at apex, densely brown or orange resinous glandular, prominently 8- or 9-ribbed. Fl. Apr-May, fr. Jul-Sep.

Etymology.

Due to its narrow distribution in Tibet, we give the specific epithet ( Carpinus tibetana ) referring to the name of the Xizang Autonomous Region (Tibet) of China where it is distributed.

Phenology.

Flowering from April to May and fruiting from May to September.

Habitat and distribution.

Up to now, according to our field surveys and sampling records in Chinese Virtual Herbarium (CVH), Carpinus tibetana has only been collected in Bomi and Motuo Counties (Figure 4 ). The new species usually grows at the forest edge and miscellaneous wood forest at elevations from 1550-2300 m a.s.l. This species probably extends its distribution to other Himalayan and adjacent regions in India, Nepal and Bhutan. Therefore, the Carpinus specimens collected from these regions need to be examined and confirmed and further field investigations to these regions should be conducted.

Additional specimens examined.

CHINA. Tibet: Linzhi City, Yigong River , forest edge, 2300 m, 8 Aug 1983, B.S. Li et al. 06467 & 6467 (PE); Bomi County, near to Yigong Town , secondary forest, 2100 m, 8 Sep 1976, Wu 5649 (PE); Bomi County , Tongmai , mixed forest, 2080 m, 24 Jun 1976, Anonymous 2505 (PE); Bomi County , Tongmai to Lulang along the G318 National Road , forest edge, 95°00'48'' E, 30°02'35"N, 2060 m, 26 Sep 2009, H. Sun et al. SunH-07ZX-2725 (KUN); Motuo County , Dexing, 26 Apr 1993, H. Sun et al. 6008 (PE); Motuo County , from Ani to Hanmi, forest edge, 1550 m, 19 Sep 1980, Anonymous 15079 (PE); Motuo County , forest edge, 1500 m, 29 Jun 1980, W.L. Chen 10780 (PE); Bomi County , Yigong, Tongmai, 95°04'31"E, 30°06'05"N, 2060 m, forest edge, 28 Aug 2016, Z.Q. Lu 2016QTP002 - Z.Q. Lu 2016QTP011 (LZU) .

Key for identification of these four related species in Yunnan and Tibet, China

1	Bracts with lobes at bases of inner and outer margins; petioles slender, (1.0-)1.5-3.0 cm	C. viminea
-	Bracts with an inflexed auricle at base of inner margin; petioles robust, 0.3-1.2 cm	2
2	Infructescences 4-13 cm × 1.5-3 cm; bracts 1.2-2.3 cm × 0.5-1.2 cm; nutlets ovoid-ellipsoid or broadly ovoid, with dense resinous glands, glabrous or sparsely villous at apex	3
-	Infructescence 2.5-4.5 cm × 1-1.5 cm; bracts 0.9-1.9 cm × 0.4-0.6 cm; nutlets broadly ovoid or ovoid-ellipsoid, without resinous glands, densely villous	C. mollicoma
3	Leaf blade oblong-lanceolate, ovate-lanceolate, or elliptic-lanceolate, abaxial leaf surface glabrescent, with 14-18 lateral veins on each side of midvein, average distance between lateral veins 5-8 mm; nutlets broadly ovoid, 3.2-4.6 mm × 2.9-4.1 mm	C. monbeigiana
-	Leaf blade ovate-elliptic or elliptic, abaxial leaf surface densely pubescent, with 19-24 lateral veins on each side of midvein, average distance between lateral veins 4-5 mm; nutlets ovoid-ellipsoid, 3.0-3.9 mm × 2.2-2.8 mm	C. tibetana

Figures

Figure 2. Carpinus tibetana Z. Qiang Lu & J. Quan Liu was drawn from Z. Q. Lu 2016 QTP 001 (LZU).

Figure 3. Carpinus tibetana Z. Qiang Lu & J. Quan Liu. A The whole plant B Branches with infructescences, the small white arrows pointing to the infructescences C Leaf D Bract and fruit.

Figure 4. Morphological clustering based on Principal Component Analyses separated three different groups responding to the respective species.