Ilex venusta H.Peng & W.B.Liao, 2017

Jiang, Lei, Xu, Kewang, Fan, Qiang & Peng, Hua, 2017, A new species of Ilex (Aquifoliaceae) from Jiangxi Province, China, based on morphological and molecular data, Phytotaxa 298 (2), pp. 147-157 : 149-154

Ilex venusta H.Peng & W.B.Liao , sp. nov. ( Figs. 3–6 )

Type:— CHINA. Jiangxi: Ganzhou City , Shangyou County, Guanggu Mountain , 25°54’N, 114°03’E, elev. 1107 m, 27 October 2016, Xu & Zhao XKW183 (holotype: KUN!; isotypes: SYS!, PE!, A!) .

This new species is a member of Ilex sect. Paltoria and can be distinguished from other sections in Ilex by solitary pistillate inflorescence. Ilex venusta is similar to I. viridis , I. triflora , but I. venusta differs in its narrow leaves, slender trunk and drooping branches ( Table 3).

Shrubs, 1.0– 2.5 m tall, 1–2cm in diameter. Bark grey to brownish. Branchlets of first and second year slender, pendulous, green, terete, longitudinally ridged slightly apically, puberulent. Leaves persist one–three years on branchlets. Stipules deciduous, brown, lanceolate, ca. 0.7 mm; petiole 1.9–2.7 mm, puberulent. Leaf blade abaxially light green, adaxially green, narrowly lanceolate, (1.3)–4.0–(5.5) × (0.6)–0.8–(1.2) cm, leathery, abaxially conspicuous dark punctate, midvein deeply sulcate and pubescent, lateral veins in 5–8 pairs, base cuneate, margin slightly recurved, crenate-serrate, apex acute. Pistillate inflorescences 1-flowered in cymes, solitary, axillary on current year branchlets; pedicels 0.6–1.0 cm, puberulent, gradually enlarged toward distal half; bracteoles 2, brown, small, subulate. Fruit dark purple to black, globose or slightly depressed globose, 7–11 mm in diam.; fruiting pedicel (1.2)–1.6–(1.8) cm, puberulent, usually purple in the upper part of the pedicel; calyx persistent, explanate, ca. 2 mm in diam., dark purple; stigma persistent, discoid; pyrenes 4, sometimes 1–3 caused by abortion, ellipsoidal, 4–5 × 3–4 mm in diam., abaxially 2–3 slightly striate, not sulcate, endocarp leathery.

Stomatal morphology:— The stomatal type ( Fig. 5A ) of this new species is amphicyclocytic, which is the most common and basic type of Ilex . It has two kinds of abaxial stomata, normal ( Fig. 5B ) and giant ( Fig. 5C ). This is another unique characteristic in Ilex . The mean size of the normal stomata is 31×26 μm, which is relatively large compared with other species in this genus ( Li et al. 2010). The mean size of giant stomata is 52×44 μm.

Distribution:— This new species is currently only found in Jiangxi Province, China ( Fig. 6 ). We have found two populations ( Table 4) during the field investigations in the Luoxiao Mountains. We suspect that this new species probably occurs in the neighboring Hunan Province.

Habitat:— It occurs under subtropical evergreen broadleaved forests and mixed broadleaf-conifer forest in the middle or on the top of the mountain, 1107–1390 m. The dominant tree species of the community at the first site include Pinus massoniana Lamb. ( Pinaceae ), Fokienia hodginsii (Dunn) A. Henry & H.H. Thomas ( Cupressaceae ), Schima argentea E. Pritz. ( Theaceae ), Adinandra millettii (Hook. & Arn.) Benth. & Hook. f. ex Hance ( Pentaphylacaceae ). There are also Litsea elongata (Nees) Hook. f. ( Lauraceae ), Liquidambar formosana Hance ( Altingiaceae ), Castanopsis eyrie (Champ. ex Benth.) Tutcher ( Fagaceae ) and Castanopsis lamontii Hance ( Fagaceae ) in the community at the site of the second population.

Phenology:— Flowering April–May and fruiting June–November.

Etymology:— The specific epithet venusta , which means comely, refers to the slender trunk and branches and its small, narrow leaves.

Vernacular name:—This species is called Xiǎoyèqîng(Ṭộḽ, literally translated as ‘small green leaves’) by local people at Wuzhifeng Town, Shangyou County. We would like to give it a Chinese name, Xiānxiù Dōngqīng (" ‵ķḽ) to reflect its distinctly slender style.

Additional specimens examined:— CHINA. Jiangxi: Ganzhou City, Shangyou County, Wuzhifeng National Forest Park , Mt. Yingpan , 25°59′N, 114°08′E, elev. 1390 m, 11 July 2016, Fan, Xu & Zhao XKW174 ( KUN!; SYS!) .

Figures

FIGURE 3. Ilex venusta. A. plant; B. abaxial surface of leaf blade; C. abnormal pyrene caused by abortion; D. normal pyrene. Drawn by L. Jiang.

FIGURE 4. Ilex venusta. A. plant and habitat; B. leaves; C. infructescence; D. puberulent branch; E. fruit; F. dark glands on abaxial surface of leaf blade; G. leaf blade; H. pyrenes. A–E: photographed by K.W. Xu; F–H: photographed by L. Jiang.

FIGURE 5. Scanning electron micrographs of stomata of I. venusta and I. viridis. A–C, I. venusta; D–F, I. viridis.

FIGURE 6. Distribution of Ilex venusta, I. triflora, and I. viridis in China.