全 文 ：Recieved： 2014–01–13　　　　Accepted： 2014–01–22
This study was supported by the Project “Compilation of the Chinese Version of Flora of Hong Kong” (AFCD/SQ/110/11) Agriculture, Fisheries and
Conservation Department, the Hong Kong Special Administrate Region.
* Corresponding author. E-mail: nhxia@scib.ac.cn
热带亚热带植物学报　2014， 22(2)： 121 ~ 124
Journal of Tropical and Subtropical Botany
During a recent botanical expedition to Violet
Hill in Hong Kong, China, a fruiting shrubby plant of
the genus Carpinus L. of Betulaceae caught our
attention. This plant, obviously belonging to section
Carpinus because of the presence of asymmetric and
loosely overlapping bracts of female flowers and
the nutlets with prominent ribs as well, had not been
previously recorded from Hong Kong. After careful
comparison of the plant with herbarium material and
consultation of relevant literature[1–4], we are forced to
the conclusion that it represents a new species, which
we describe below.
Carpinus insularis N. H. Xia, K. S. Pang & Y. H.
Tong, sp. nov. (Fig. 1)
Type: China. Hong Kong: Violet Hill, 22°14′25.30′′
N, 114°11′55.04′′ E, alt. 190 m, 21 Aug. 2013, K. Y.
Tam s. n. (holotype, IBSC; isotype, HK).
Diagnosis: This species is similar to C. hebestroma
Yamamoto and C. polyneura Franch., but differs from
香港桦木科一新种——香港鹅耳枥
童毅华1,2, 彭权森3, 夏念和1*
(1. 中国科学院华南植物园， 中国科学院植物资源保护与可持续利用重点实验室， 广州 510650； 2. 中国科学院大学， 北京 100049; 3. 香港渔农
自然护理署香港植物标本室， 香港)
摘要： 报道了桦木科(Betulaceae)鹅耳枥属(Carpinus L.)一新种——香港鹅耳枥(C. insularis N. H. Xia, K. S. Pang & Y. H. Tong)。
香港鹅耳枥与太鲁阁鹅耳枥(C. hebestroma Yamamoto)及多脉鹅耳枥(C. polyneura Franch.)相似，但习性灌木状，叶具 13 ~ 16 对
侧脉，先端锐尖，边缘锯齿的芒尖较短，果苞宽半卵形或半卵形，长 8 ~ 14 mm，小坚果顶端密被长柔毛且疏具树脂状腺体，与后
两者易于区别。
关键词： 桦木科； 鹅耳枥属； 香港鹅耳枥； 香港； 新种
doi: 10.3969/j.issn.1005–3395.2014.02.002
Carpinus insularis (Betulaceae), A New Species from Hong Kong, China
TONG Yi-hua1,2, PANG Kuen Shum3, XIA Nian-he1*
(1. Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences,
Guangzhou 510650, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. Hong Kong Herbarium, Agriculture, Fisheries
and Conservation Department, Hong Kong, China)
Abstract: A new species of Carpinus L. in the Betulaceae, C. insularis N. H. Xia, K. S. Pang & Y. H. Tong, is
described and illustrated. The new species is similar to C. hebestroma Yamamoto and C. polyneura Franch., but
differs in its shrubby habit, 13 – 16 pairs of lateral veins of leaves, acute leaf apex, shorter mucrones of the leaf
marginal teeth, fruiting bracts 8 – 14 mm long, broadly semi-ovate or semi-ovate, and nutlets sparsely resinous-
glandular and densely villous at apex.
Key words: Betulaceae; Carpinus L.; Carpinus insularis; Hong Kong; New species
122 第22卷热带亚热带植物学报
Fig. 1 Carpinus insularis N. H. Xia, K. S. Pang & Y. H. Tong, sp. nov. A: Fruiting branch; B: Adaxial leaf surface; C: Nutlet; D: Broadly semi-ovate
fruiting bract (right: adaxial view; left: abaxial view); E: Semi-ovate fruiting bract (right: adaxial view; left: abaxial view). (Drawn by Ding-han CUI
from the holotype)
第2期 123
them by having a shrubby habit, 13 – 16 pairs of lateral
veins, an acute leaf apex, shorter mucrones of the
leaf marginal teeth, fruiting bracts 8 – 14 mm long,
broadly semi-ovate or semi-ovate, and nutlets sparsely
resinous-glandular and densely villous at apex.
Deciduous shrubs 3 m tall; bark grey. Branchlets
purplish brown, initially sparsely villous and lenticellate,
later glabrescent. Petiole 6 – 10 mm, adaxially villous
and pubescent initially, later glabrescent, abaxially
pubescent or glabrous; leaf blade ovate-lanceolate, 4 –
6 cm × 1.5 – 2 cm, thickly papery, midvein adaxially
and abaxially villous, lateral veins abaxially villous
with barbate axils, base rounded, margin simply
mucronate-serrate (or rarely doubly mucronate-serrate)
with short mucrones to 0.3 mm long on the serrations,
apex acute, lateral veins 13 – 16 on each side of midvein.
Infructescence together with peduncle 3 – 4 cm long,
villous and pubescent; fruiting bracts asymmetric,
semi-ovate or broadly semi-ovate, 8 – 14 mm × 3 –
5 mm, villous along veins, outer margin irregularly
dentate, without basal lobe, inner margin entire or
slightly dentate towards the apex, with inflexed basal
auricle, apex acute, veins 4 – 5, reticulate veins
prominent. Nutlets ovoid, 2.5 – 3.5 mm long, spar-
sely resinous-glandular, densely villous at apex, pro-
minently 8 – 10-ribbed.
Distribution and habitat: Carpinus insularis
is currently known only from the type locality. It grows
in thickets on a hill slope at an altitude of 190 m. In the
type locality we found only a population comprising
about ten mature individuals within an area of about
100 m2 on a steep slope, and we failed to discover
other populations despite an exhaustive search.
Phenology: Flowering time unknown; fruiting
from August to October.
Etymology: The specific epithet “insularis” refers
to the occurrence of the new species in Hong Kong
Island.
Notes: Carpinus insularis is similar to both C.
hebestroma Yamamoto endemic to Taiwan[3] and C.
polyneura Franch. from the mainland China in the
general aspect of leafy branches and in the leaf shape,
but differs in the shrubby habit, 13 – 16 pairs of lateral
veins of leaves, acute leaf apex, shorter mucrones of the
leaf marginal teeth, fruiting bracts 8 – 14 mm long,
broadly semi-ovate or semi-ovate, and the nutlets
sparsely resinous-glandular and densely villous at
apex. A detailed comparison of the three species is
given in Table 1.
Six species and one variety of Carpinus had been
previously reported from Guangdong and Hainan[5],
both closely adjacent to Hong Kong. All of these taxa
are trees confined in mountainous areas at altitudes of
450 – 1600 m in northern Guangdong except for one
variety, i.e., C. londoniana H. Winkl. var. lanceolata
(Hand.-Mazz.) P. C. Li, which occurs in montane
forests at altitudes of 600 – 800 m in Changjiang
and Ledong, Hainan[5]. Our new species is at once
distinguishable from all these taxa by the shrubby
habit.
Table 1 Comparison of Carpinus insularis, C. hebestroma and C. polyneura
Character C. insularis C. hebestroma C. polyneura
Habit Shrub Tree Tree
Lateral veins of leaves 13 – 16 pairs 11 – 12 pairs 16 – 22 pairs
Shape of leaf apex Acute Acute or acuminate Acuminate or caudate
Length of mucrones of serrations (mm) 0.3 0 1
Shape of bracts Semi-ovate or broadly semi-ovate Broadly semi-ovate Semi-ovate or broadly semi-ovate
Indumentum of nutlets Densely villous at apex Usually pubescent Densely villous at apex and sparsely pubescent
elsewhere
Resinous glands on nutlets Present Present Absent
Distribution Hong Kong Taiwan Fujian, N Guangdong, Guizhou, Hubei, Hunan,
Jiangxi, Shaanxi, Sichuan, Zhejiang
童毅华等：香港桦木科一新种——香港鹅耳枥
124 第22卷热带亚热带植物学报
The genus Carpinus, comprising about 50 species,
is mainly distributed in temperate regions of the Northern
Hemisphere[6] with some extending to subtropical and
tropical montane regions[7]. Carpinus insularis is the
first species of the genus found to occur in the
lowland area near the Tropics of Cancer. Its discovery,
therefore, is important for a better understanding of
the phytogeography and dispersal of Carpinus.
Acknowledgements　　We are grateful to the Directors and
Keepers of the A, IBSC, IBK, P and TAI herbaria for allowing
to examine their specimens or scanned specimen photos. Our
thanks also go to Prof. Khoon Meng WONG and Prof. Qin-er
YANG for their comments on the manuscript, and Mr. Ding-
han CUI for preparing the illustration.
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