Ocotea zahamenensis van der Werff, 2013

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 : 273

35. Ocotea zahamenensis van der Werff , sp. nov.

( Figs 14 , 5 )

Ocoteae perforatae similis, sed ramulis gemmisque terminalibus pubescentibus, domatiis axillis venarum lateralium restrictis recedit.

TYPUS. — Madagascar, Toamasina, Parc National de Zahamena , Manakambahiny-Est , 17°38’25’S, 48°38’34’’E, 989 m, 27.III.2000, fl., S. Randrianasolo, T. Razafindrabeaza, L. M. Randrianjanaka & A. Razakanirina 155 (holo-, P [ P00713426 ] ; iso-, MO [ 2299153 ]) .

PARATYPES. — Madagascar. Antananarivo. c. 7 km E of Anjozorobe , Lowry & Randrianasolo 4387 ( MO, P [ P01977631 ]) ; Toamasina. Parc National de Mantady, Rahajasoa et al. 167 ( MO, P [ P01977630 ], TAN) ; Toamasina, Moramanga, Commune Ambohibary , 22 km NE de Moramanga, Rakotovao et al. 1287 ( MO, P [ P06837194 ]) ; Toamasina, PN de Zahamena , Rokotondrajaona 148 ( MO, P [ P01977626 ]) ; Toamasina, c. 15 km NE of Moramanga, Phelps Dodge project site, Rakotomalaza 1082 ( MO, P [ P01977629 ]) ; Taomasina, Route Analamy Rakotomalaza et al. 1328 (MO, P) .

DISTRIBUTION. — This species is known from the middle and upper eastern slopes from Ranomafana to Zahamena between 900 and 1500 m altitude.

PHENOLOGY. — Flowering: February; fruiting: May to October.

DESCRIPTION

Trees, 9- 15 m. Twigs terete, densely grey or brown appressed pubescent, the indument wearing off with age; terminal buds densely pubescent. Leaves 5-10 × 2.5-4.3 cm, firmly chartaceous, alternate, elliptic to broadly elliptic, glabrous or with a few scattered, appressed hairs when young, base obtuse to acute, apex acute, lower surface densely and minutely gland-dotted, lateral veins c. 5 on each side, immersed and only faintly visible, reticulation weakly raised on the lower surface, not visible on upper surface, domatia consisting of pits in the axils of the lowermost lateral veins, glabrous, not present on all leaves. Petioles 1-1.5 cm, flat or shallowly canaliculate. Inflorescences 4-7 cm long, laxly branched, paniculate-cymose, sparsely pubescent, mostly in the axils of deciduous bracts. Flowers green or white-yellow, 5-6 mm in diameter, tepals 6, equal, 2 mm long, moderately to densely pubescent outside, pubescent inside, spreading at anthesis; stamens 9, all 4-celled, 1.5 mm long, the filaments pubescent, half as long as the mostly glabrous anthers, staminodia stipitiform, 1 mm long, pubescent, glands present at the base of the inner stamens; pistil 2.5 mm long, glabrous, ovary 1 mm long, stigma discoid, receptacle deeply cupshaped, appressed pubescent inside. Fruit, when young, completely enclosed in the cupule, larger immature fruit 1 × 1 cm, ¾ enclosed in the cupule.

REMARKS

Ocotea zahamenensis sp. nov. is known from several collections along the upper part of the wet eastern slope of Madagascar. It is characterized by the conspicuous domatia in the axils of the basal lateral veins, the appressed indument on the twigs and terminal buds and its pinnate venation. Somewhat similar species are O. perforata , which has glabrous twigs and terminal buds and which has pit domatia along the lateral veins, O. foveolata , which has tripliveined leaves and O. humbertii and O. tsaratananensis , both of which have an erect, pilose indument along the young twigs and inflorescences. Ocotea tsaratananensis also differs in the presence of close, conspicuous bract scars at the beginning of seasonal growth; such conspicuous scars are lacking in O. zahamenensis sp. nov. All are species of higher altitudes. Provisionally placed here are three collections from Fianarantsoa: one from Parc National de Andingitra (Messmer & Randrambololona NM 877) with somewhat larger leaves; it has a mature fruit, 3 × 2 cm, and a cupule 2 cm wide and 1 cm deep and two sterile collections (Kotozafy et al. 890 and 892) from the National Park Ranomafana near Vohiparara.

Figures

FIG. 14. — Isotype of Ocotea zahamenensis van der Werff, sp. nov. (“zahamensis” on the label).

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. («).