Machilus coriacea A.Chev., 2023

De Kok, Rogier P. J., 2023, The Lauraceae Juss. of Indo-China: fifteen new species, four new combinations and two neotypifications, Adansonia (3) 45 (1), pp. 1-25 : 18-20

13. Machilus coriacea A.Chev. ex de Kok, sp. nov. ( Figs 12 ; 14 )

Machilus coriacea A.Chev. unpublished; P.H.Hô, Câycỏ Việtnam 1: 489 ( Hô 1991), nom. inval.; Nguyén Kim Đào, Lauraceae in Checklist of Plant Species of Vietnam 2: 101 (Nguyén Kim Đào 2003), nom. inval.; Nguyén Kim Đào, Flora of Vietnam 20: 95 (Nguyén Kim Đào 2017), nom. inval.

DIAGNOSIS. — This species differs from its close relative Machilus grandibracteata S.K.Lee & F.N.Wei , which has twigs that are glabrous and leaves with 9-11 pairs of secondary nerves (while M. coriacea A.Chev. ex de Kok , sp. nov. has sparsely hairy twigs and leaves with 7-9 pairs of secondary nerves); inflorescence which are densely hairy and perianth lobes which are sparsely hairy inside and outside (while M. coriacea A.Chev. ex de Kok , sp. nov. has inflorescence which are sparsely hairy and perianth lobes densely hairy inside and outside).

TYPE SPECIMEN. — [ Vietnam] Bien Hoa : Dinh Quan, 11°9’24.66”N, 107°15’8.928”E, 4.XII.1932, Poilane 21630 (holo-, P [ P02004544 ]; iso-, E[no barcode]) .

VERNACULAR NAME. — Vietnamese: Kháo dai (Nguyén Kim Đào 2017: 95).

DISTRIBUTION. — Vietnam (see Fig. 12 ).

ECOLOGY. — Growing in forest, sometimes over limestone, between 1000-1500 m altitude. Flowering from Nov. to January; fruiting in Sept.

CONSERVATION. — Endangered B2ab(i,ii,iii,iv) This species is only known from five collections from Vietnam. An analysis of the Extent of Occurrence (EOO) and Area of Occupancy (AOO) gives an IUCN Conservation Assessment of Endangered.

ADDITIONAL COLLECTIONS SEEN. — Vietnam. Nha Trang: Massif du Hon-Ba, 12°22’59.988”N, 108°52’59.988”E, alt. c. 1000-1500 m, 1.IX.1918, Chevalier 38881 ( P00476642 , P02004595 , P02004596 , P02004597 ) ; Lang Son: Bang Mac , 17.I.1941, Pételot 6729 ( P) ; Vinh: Tam Dao , 21°20’7.008”N, 105°35’21.012”E, IV.1931, Pételot 4680 ( P02008991 ) ; Saigon: Hoc-Môn , 10°53’16.008”N, 106°35’39.012”E, XI.1942, Anonymous 9197 ( P02003810 ) .

DESCRIPTION

Trees 10-20 m tall, dbh 20-25 cm. Twigs slender, 1.6-3 mm thick, rounded in cross-section, sparsely hairy; hairs appressed, yellowish; terminal leaf bud ovoid 5-7 mm long, apex acute, velutinous, imbricate. Leaves alternate; blade elliptic to oblanceolate, 6-16 × 2.5-7.6 cm, apex acute, base cuneate, leathery, penninerved, secondary nerves 7-9 pairs, curved towards margin, tertiary nerves scalariform-reticular; upper surface glabrous, midrib and secondary nerves sunken, tertiary nerves indistinct; lower surface sparsely hairy, midrib and secondary nerves raised, tertiary nerves distinct; hairs yellowish, erect; petiole channelled, 18-20 mm long, sparsely hairy, slender.

Inflorescence 10-15 cm long, terminal, sparsely hairy; bracts leaf-like; bracteoles linear, c. 2 mm long. Flowers white; perianth lobes 2.4-4.5 × 1.1-1.4 mm, apex acute, densely hairy inside and outside; stamens 9, 3.4-4 mm long, glabrous; ovary c. 0.7 mm diam.

Fruit globular, 18-20 × 16-18 mm, apex rounded, glabrous; perianth lobes 7.5-8 × 2.9-3.6 mm, apex acute, densely hairy, erect, patent to reflexed, membranous (see Fig. 14 ).

Figures

FIG. 12. — Distribution of Litsea rubrobrunnea de Kok, sp. nov. (), Litsea salmonea A.Chev. ex de Kok, sp. nov. (), Machilus coriacea A.Chev. ex de Kok, sp. nov. (), Neocinnamomum huongsonensis Kim Dao, sp. nov. () and Phoebe petelotii Kosterm. ex de Kok, sp. nov. ().

FIG. 14. — Holotype of Machilus coriacea A.Chev. ex de Kok, sp. nov., held at the Muséum national d’Histoire naturelle in Paris (P02004544).