Ocotea trichantha Baker

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 : 271

32. Ocotea trichantha Baker

( Fig. 10 )

Journal of the Linnaean Society 22: 515 (1887).

— Typus: Madagascar. Without further data, fls, Baron 4373 (holo-, K ; iso-, P [ P00541637 (under erroneously Baron 4979 in SONNERAT), P00541638 ]!) .

SELECTED SPECIMENS SEEN. — Centre, Ravin boisé dans l’Isalo au NW de Ranohira , Service Forestier (Capuron) 28280 (MO, P[P01977641], TEF) ; Toliara, Forêt d’Analavelona, 1.5 km NO d’Andranoheza, Randriantafika & Rakotovao 227 (MO, P[P01977644]) .

DISTRIBUTION. — This species has been collected at Andiamanero (Ihosy), near Isalo and the Massif d’Analavelona at altitudes from 600-1300 m.

PHENOLOGY. — Flowers: August, September, December; fruits: December.

VERNACULAR NAMES. — Maroanaka (Bara dialect), varongy.

DESCRIPTION

Tree, to 25 m tall. Twigs terete, densely light brown-tomentellous, becoming glabrous with age; terminal buds densely tomentellous. Leaves alternate, firmly chartaceous, 5-9 × 2.5-5 cm, elliptic to broadly elliptic, base acute or obtuse, tip obtuse or acute, upper surface shiny, glabrous or with some hairs near base of midrib, lower surface dull, glabrous or with some scattered, small, appressed hairs; lateral veins 3-5, venation immersed on upper surface, raised on lower surface, domatia present, often several pairs on a leaf, consisting of rather shallow pockets, this sometimes with a fringe of hairs. Petioles 0.9-1.3 cm long, with similar indument as twigs. Inflorescences in axils of bracts close to terminal buds (sometimes appearing in axils of normal leaves, but on closer inspection along a leafless short shoot), densely pubescent, to 4 cm long. Flowers white. Tepals 6, pubescent on both surfaces, 1.5-2 mm long; stamens 9, 4-celled, filaments and anther dorsally pubescent, 1.5 mm long, filament shorter than anther; staminodia 3, stipitiform, pubescent. Ovary and inside of receptacle glabrous. Cupule deeply cup-shaped, 1.5 cm wide, 1.1 cm high, fruit ellipsoid, 2 × 1.5 cm.

REMARKS

This species can be recognized by its short, densely pubescent inflorescences, alternate, few-veined leaves (at times approaching the tripliveined condition) and the densely tomentellous twigs. Most collections of this species are sterile or with fruits; the description of the flowers is based on the collection SF 28280 Capuron. The presence of inflorescences in axils of deciduous bracts and not in axils of normal leaves, is unusual among Ocotea species in Madagascar, but occurs also in the related O. malcomberi . This species differs from O. trichantha in its much longer and less densely pubescent inflorescences. More similar to O. trichantha is O. ivohibensis sp. nov., which differs in its sparsely pubescent flowers, erect hairs on lower leaf surface and the reddish hairs covering the domatia.

Figures

FIG. 10. — Distribution of Ocotea madagascariensis (Meissner) Palacky (N), O. nervosa Kosterm. (p), O. trichantha Baker (l), O. trichophlebia Baker (Ì) and O. tsaratananensis van der Werff («).