Cryptocarya kaengkrachanensis M.Z.Zhang, Yahara & Tagane, 2020

Zhang, Meng, Yahara, Tetsukazu, Tagane, Shuichiro, Rueangruea, Sukid, Suddee, Somran, Moritsuka, Etsuko & Suyama, Yoshihisa, 2020, Cryptocarya kaengkrachanensis, a new species of Lauraceae from Kaeng Krachan National Park, southwest Thailand, PhytoKeys 140, pp. 139-157 : 139

Cryptocarya kaengkrachanensis M.Z.Zhang, Yahara & Tagane sp. nov. Fig. 2

Diagnosis.

Cryptocarya kaengkrachanensis resembles C. amygdalina in having pinnately veined, leathery leaves apparently glabrous (microscopically hairy) below, young twigs with yellowish brown hairs and fruits 1.36-1.85 times longer than width. However, C. kaengkrachanensis differs from C. amygdalina (Fig. 3 ) in having the leaves ovate and elliptic to narrowly elliptic (vs. oblong-lanceolate) with leaf aspect ratio from 1.38 to 2.28 (vs. 2.46-3.43) (Fig. 4 ), and fruits ovoid (vs. ellipsoid) with the stalk distinctly swollen (vs. not or only slightly swollen). While C. kaengkrachanensis was sister to C. albiramea in MIG-seq tree, C. kaengkrachanensis is distinguished from C. albiramea by elliptic leaves with leaf aspect ratio less than 2.5 (vs. oblong-lanceolate leaves with leaf aspect ratio more than 2.5).

Type.

THAILAND. Phetchaburi Province: Kaeng Krachan National Park, 960 m elev., 12°49'19.7"N, 99°21'57.7"E, 23 Oct. 2013, Tagane S., Nagamasu H., Naiki A., Rueangruea S., Suddee S., Fuse K., Keiwbang W., Pansamrong P. T2069 [fr.] (holotype KYO!, isotypes BKF!, FU!, KAG!).

Description.

Trees up to 12 m tall. Young twigs densely covered with appressed short yellowish to brown hairs, old twigs lenticellate, terete and slightly hairy. Leaves alternate; blade leathery, ovate, elliptic to narrowly elliptic, the range (and average ± SD) of leaf length (cm) is 2.6-10.3 long (7.2 ± 2.5, n=17), the range (and average ± SD) of leaf width (cm) is 1.5-6.4 (4.2 ± 0.6, n=17) wide leaf aspect ratio from 1.38 to 2.28, obtuse or retuse at apex in adult trees, acuminate in young trees, broadly cuneate at base, green and not lustrous above and slightly glaucous below when fresh, brown above and grey brown below when dry, apparently glabrous but microscopically sparsely hairy below; pinnately veined, midrib sunken above, raised below, secondary veins 6 or 7 pairs, slightly sunken above, raised below, tertiary veins scalariform-reticulate, faintly visible above, raised below; the range (and average ± SD) of petiole length (cm) is 0.7-1.5 long (1.1 ± 0.22, n=10), flat above, rounded below, dark brown when dry, covered with short yellowish hairs. Inflorescences and flowers not seen. Infructescence axillary, 4-17 cm long (8.4 ± 3.4, n=16) (the range, average ± SD), rachis hairy, lenticellate; bracteoles not seen. Immature fruits ovoid, 9.9-13.8 mm long (11.49 ± 1.28, n=14), 5.8-9.7 mm wide (7.53 ± 2.36, n=14) with aspect ratio 1.36-1.85 (1.54 ± 0.14, n=14). yellow green when fresh, dark brown when dry, shortly hairy. Fruiting stalk slightly swollen, rough, light brown when fresh, dark brown when dry. Mature fruits not seen.

Other specimens of C. kaengkrachanensis examined.

THAILAND. Phrae Province: between Ban Nam Krai and Pha Tuem, 16 Apr 1970, Smitinand T., Cheke A.S. 10817 [BKF 46511!]. Phetchaburi Province: Kaeng Krachan National Park, 960 m elev., 12°49'19.7"N, 99°21'57.7"E, 23 Oct. 2013, Tagane S., Nagamasu H., Naiki A., Rueangruea S., Suddee S., Fuse K., Keiwbang W., Pansamrong P. T1883 (BKF!, FU!). Kanchanaburi Province: Thong Pha Phum District, Pilok, at the Thai-Burmanese border. C. 900 m. 14 41.0'N, 98 21.8'E, tree 12m, 25 January 2009 [fr.], Middleton D.J., Karaket P., Lindsay S., Suddee S. 4785 [BKF 182421!].

Distribution.

Endemic to Thailand. The new species is currently only known in a few protected areas of Phrae, Phetchaburi and Kanchanaburi Provinces including Kaeng Krachan National Park.

Etymology.

The specific epithet kaengkrachanensis is derived from the name of the national park from which the species has first been recorded.

Conservation status.

Least Concern ( IUCN 2012, 2017). This species occurs in hill evergreen forests of some protected areas including Kaeng Krachan National Park and there is no sign of declining trends.

Figures

Figure 2. Cryptocarya kaengkrachanensis M. Z. Zhang, Yahara & Tagane A branch with immature fruit B lower leaf surface C holotype: Tagane et al. T 2069 (KYO) D young branchlet E part of an infructescence with immature fruits F longitudinal sections of an immature fruit.

Figure 3. Cryptocarya amygdalina A leafy branchlet B lower leaf surface C specimen Tagane et al. T 3090 (KYO) D lower leaf surface (dry) E fresh immature fruit F dried fruit.

Figure 4. Scatter plot of leaf aspect ratio (horizontal axis) and circularity (vertical axis). Solid circles: Cryptocarya amygdalina, solid triangles: C. kaengkrachanensis.