Ocotea involuta Kosterm.

Werff, Henk Van Der, 2013, A revision of the genus Ocotea Aubl. (Lauraceae) in Madagascar and the Comoro Islands, Adansonia (3) 35 (2), pp. 235-279 : 256

17. Ocotea involuta Kosterm.

( Fig. 5 )

Communication (Pengumuman) of the Forest Research Institute, Indonesia 60: 16 (1957).

TYPUS.— Madagascar. Ambatolampy. 12.XII.1949, fls, Service Forestier 1051 (holo-, P [ P00541627 ]! ; iso-, TAN, TEF) .

SELECTED SPECIMENS SEEN. — Mahajanga. Mangindrano, petit plateau dans la forêt dense humide de montagne. Callmander et al. 427 (MO, P[ P02002154 ], TAN) ; Mahajanga, forêt de crête au Nord du campement Bemafo, Buerki et al. 110 (MO, P) ; Antsiranana, SAVA Region, Ambohimirahavavy , Rakotovao et al. 2536 (MO, P[P02002153], TAN) ; Antsiranana, Tsaratanana Massif, 12 km north of Mangindrano, Birkinshaw 922 (MO, P[ P01991806 ]) .

DISTRIBUTION. — Ocotea involuta is known from the type locality, Ambatotsipihina, district of Ambatolampy and the Tsaratanana-Mangindrano area much further north. Altitudinal distribution is only known for the northern populations and is between 1700 and 2200 m.

PHENOLOGY. — Flowers: October-December; fruits: October.

DESCRIPTION

Tree, 15- 25 m. Twigs angular, pubescent, the indument largely covering the surface, but wearing off with age; terminal buds brown-tomentellous. Leaves alternate, coriaceous, elliptic, 4-6 × 1.5-2 cm, apex obtuse, base decurrent on petiole with two inrolled lobes, upper surface glabrous, venation immersed, scarcely visible, lower surface sparsely appressed pubescent, becoming glabrous, midrib slightly raised, otherwise venation immersed and scarcely visible, somewhat glaucous, margin inrolled, more strongly so towards the base with two inrolled lobes; lateral veins scarcely visible, 5-6; domatia lacking. Petioles appressed pubescent, flat, 5-6 mm from twig to inrolled lobes. Inflorescences in axils of leaves or bracts, brown-tomentellous, 3-5 cm long. Flowers 5 mm in diameter, tepals 6, equal, spreading at anthesis, c. 1.8 mm long, outside sparsely pubescent to almost glabrous, inside pubescent; stamens 9, 4-celled, 1.5 mm long; filaments pubescent, inner stamens with a gland near the base, staminodes 3, stipitiform, the lower half pubescent, pistil glabrous, receptacle glabrous or pubescent inside.Tepals deciduous in old flowers. Fruit ellipsoid, c. 1 × 0.8 cm; cupule bowl-shaped, 1 cm wide and 0.5 cm high.

REMARKS

Ocotea involuta is best recognized by the inrolled lobes at the base of the leaves, the small leaves and the brown-tomentellous twigs. Differences with O. rigidifolia Kosterm. are mentioned under that species. It can also be mistaken for a small-leaved O. auriculiformis , but that species has larger leaves with the reticulation raised and auriculate lobes are smaller. Ocotea involuta , as accepted here, is a variable species. The type is from Ambatolampy, south of Antananarivo and has the receptacle glabrous inside. The other collections are from the Tsaratanana-Mangindrano much further north and have the inside of the receptacle appressed pubescent. The northern collections vary somewhat in leaf shape and inflorescence length among themselves and it seems for the time being best to accept O. involuta in a broad sense. However, if additional collections from the type locality show consistent differences between the northern and southern populations, the northern populations may be described as an additional species.

Figures

FIG. 5. — Distribution of Ocotea faucherei (Danguy) Kosterm. (N), O. humbertii Kosterm. (p), O. humblotii Baill. (l), O. involuta Kosterm. (Ì) and O. zahamenensis van der Werff, sp. nov. («).