Ocotea ivohibensis 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 : 256-257

18. Ocotea ivohibensis van der Werff , sp. nov.

( Figs 8 , 9 )

Ocoteae trichanthae similis, sed floribus sparse pubescentibus, foliis acuminatis, domatiis trichomatibus rubris ornatis recedit.

TYPUS. — Madagascar. Fianarantsoa, Ivohibe, Réserve spéciale d’Ivohibe , 22°29.8’S, 46°57.3’E, 1600 m, 25.X.1997, fl., Messmer et al. 506 (holo-, P [ P00648795 ]! ; iso-, G, MO [ 2299151 ]) .

PARATYPES. — Madagascar. Pic d’Ivohibe, 1500-2000 m, 5-11.XI.1924, fl., Humbert 3332 ( MO, P [ P01991805 ], TAN) ; Toliara. Betroka, Ivahona , Réserve spéciale de Kalambatritra , Andrianjafy et al. 594 ( MO, P, TAN) ; Fianarantsoa. Iakora, Begogo , Bekora , forêt de Sahalava , Andrianjafy et al. 770 ( MO, P, TAN) .

DISTRIBUTION. — Ocotea ivohibensis sp. nov. is known from few collections from the Ivohibe massif and the special reserve Kalambatritra in south-central Madagascar between 1200 and 1600 m altitude.

PHENOLOGY. — Flowers: October-November; fruits: June, August.

VERNACULAR NAMES. — Antafonana, Valotra, Varongi mainty.

DESCRIPTION

Tree, 12 m. Twigs terete, moderately to densely pubescent, the hairs short, erect, becoming glabrous with age. Terminal buds densely pubescent, the surface not visible. Leaves alternate, 4-10 × 2-6 cm, chartaceous, the upper surface sparsely pubescent or glabrous, lower surface moderately pubescent, the hairs erect, curly, denser along the major veins or glabrous except for some hairs along the major veins; the base acute to obtuse, the apex acute to acuminate, acumen to 1 cm long; gland dots not visible on the leaves; lateral veins 2 to 5 pairs, impressed on the upper surface, raised on the lower surface, tertiary venation raised on the lower surface, immersed or impressed on the upper surface; domatia present in the axils of the basal 2-3 pairs of lateral veins, consisting of a depression largely covered by reddish hairs, the domatia visible as bumps on the upper surface. Petioles 4-7 mm long, flat above, with a similar indument as the twigs. Inflorescences slender, 2-6 cm long, racemose or with 1 or 2 cymes basally, few-flowered, moderately to sparsely pubescent, the hairs ascending to erect, in the axils of leaves or in the axils of deciduous bracts near the tips of the branches.Flowers greenish yellow, 3-4 mm in diameter, the tepals half-erect, spreading in old flowers. Tepals 6, equal, sparsely pubescent outside, pubescent inside, 2 mm long; stamens 9, all 4-celled, c. 1 mm long, glabrous; staminodia stipitiform, pubescent; two globose glands present at the base of the inner 3 stamens; pistil 1.5 mm long, glabrous; receptacle deeply cup-shaped, glabrous inside. Fruit 1.3 cm wide, 1 cm high; cupule 1.6 cm in diameter, 6 mm high.

REMARKS

Ocotea ivohibensis sp. nov. has been confused with O. trichantha Baker from which it differs as follows: Ocotea ivohibensis sp. nov. has sparsely pubescent flowers (densely pubescent in O. trichantha ), domatia covered with reddish hairs (white hairs in O. trichantha ), and the major veins slightly impressed on the upper leaf surface (immersed in O. trichantha ). In the older collection made by Humbert the hairs covering the domatia have largely fallen off; leaf shape, venation and the sparse indument on the flowers allow identification as O. ivohibensis sp. nov. The indument on the lower leaf surface of O. ivohibensis sp. nov. is variable. Some specimens have a sparse indument of erect hairs on the lamina, others have only some hairs along the major veins or are glabrous with the exception of the domatia.

Figures

FIG. 8. — Distribution of Ocotea glaberrima van der Werff,sp. nov. (N), O. ivohibensis van der Werff,sp. nov.(p), O. longipes Kosterm. (l) and Ocotea macrocarpa Kosterm. (Ì).

FIG. 9. — Isotype of Ocotea ivohibensis van der Werff, sp. nov.