Capurodendron sahafariense L. Gaut. & Naciri, 2018

Gautier, Laurent & Naciri, Yamama, 2018, Three Critically Endangered new species of Capurodendron (Sapotaceae) from Madagascar, Candollea 73 (1), pp. 121-129 : 124-127

Capurodendron sahafariense L. Gaut. & Naciri , spec. nova ( Fig. 4 , 5 ).

Holotypus: MADAGASCAR. Prov. Antsiranana: Reg. DIANA, Sadjoavato, forêt de Sahafary , 12°36’26”S 49°26’43”E, 280 m, 8.I.2007, fl. & fr., Ratovoson et al. 1217 ( G [ G00418681 ]! ; iso-: CNARP, MO [ MO-2108542 ], P [ P04568840 ]!, TAN).

Capurodendron sahafariense L. Gaut. & Naciri shares a 5-ridged fruit with C. costatum Aubrév. from which it markedly differs by its much smaller leaves (6-25 × 2-7 vs 50 × 30 mm). Its venation pattern is similar to C. ludiifolium Aubrév. which also has much larger leaves. Its leaves are similar in size to that of C. androyense Aubrév. from which it differs by its winged fruits and its venation pattern.

Shrub 2 m to small tree 10 (-15) m tall, with white latex and creviced bark; ultimate twigs 1-1.5 mm in diam., greyish glabrous. Leaves coriaceous, caducous, spirally arranged at the tip of short 1.5-6.0 mm lateral branches (brachyblasts) with scars of fallen leaves and protuberances resulting from swollen stem below leaf insertion; blade 0.6-2.5 × 0.2-0.7 cm, obovate to narrowly obovate, brownish and clearly discolorous when dry with upper side darker, glabrous except for a few minute (0.2-0.3 mm) golden trichomes at base; apex obtuse to rounded, to retuse; base narrowly cuneate, indistinctly passing to a short petiole (max. 1.5 mm long, 0.8 mm in diam.); venation inconspicuous when fresh, especially on upper side, raised on both sides on dry specimens, reticulate, secondaries 3-4 on each side, almost indistinct from tertiaries, ascending at an angle of c. 20° from primary nerve, looping near margin. Flowers grouped in clusters of 1-6 among the leaves or on leafless brachyblasts; flowering pedicels 1.5-3.5 × 0.5 mm, densely golden-villous. Sepals 5, quincuncial, glabrous inside, densely golden-villous outside, circular to ovate, apex rounded to obtuse, 2.4-3.0 × 2.4 mm, the three inner ones slightly keeled. Corolla gamopetalous with 5 lobes, glabrous, tube 1.8 mm long, lobes broadly lanceolate, 3.0 × 1.2 mm, contorted in bud, spreading at anthesis, cream-coloured when fresh. Stamens 5, filaments attached to the top of the corolla tube, the free part 0.9 mm long. Anthers pair medifixed, extrorse, 1.0 × 0.7 mm, villous, connective broad, prolonged above anthers in a triangular glabrous apex 0.9 mm long, 0.45 mm at base. Staminodes 5, alternate with respect to petals and stamens, 2.5 × 1.0 mm, densely villous with golden trichomes, carnose, connivent and concealing the ovary, spreading at apex. Ovary spherical but tapering towards style base, 1.2 mm high and broad, slightly 5-lobed, villous with golden trichomes, with 5 ovules; style 5 mm long, glabrous, 0.2 mm in diam. Fruiting pedicels 3.5 × 1.1 mm, glabrescent, with a persistent calyx. Fruit ovoid and slightly beaked, 18-20 × 10-11 mm, 5-ridged, mostly glabrous but with a pubescent base; apparently only one seed develops.

Etymology. – The epithet is derived from the name of the forest where the majority of the specimens, including the type, have been collected.

Distribution, ecology and phenology. – The species is only known from the dense dry deciduous forest on sands, in Sahafary and its SE vicinity ( Fig. 3 ), in the northern part of the Western Phytogeographical Domain ( HUMBERT, 1955). The flowering and fruiting collections were gathered between November and February.

Conservation status. – The Sahafary forest has an area of c. 12 km 2, and is well-known for being home of a range of narrow endemics, including another Sapotaceae species, Manilkara sahafariensis Aubrév. It is very unfortunate that this forest has not been included in the recent extension of Madagascar protected area network, as it is under threat of being converted to agricultural land. Under these conditions and with an EOO of 41 km 2 and an AOO of 16 km 2, C.sahafariense is assigned a preliminary IUCN conservation status of “Critically Endangered” [CR B1ab(i,ii,iii)].

Notes. – Capurodendron sahafariense has the remarkable feature of having a ridged fruit. In the genus, the only other species with ridged fruits is C. costatum , which has also leaves on brachyblasts, but with blades 2.5 times longer and 5 times broader, and which is only found in the western part of the island, from Bemaraha to Ankarafantsika, i.e. more than 450 km south-west from the Sahafary forest where the new species has been discovered. The two species might be related, but this still has to be confirmed by an undergoing molecular study. The venation pattern in C. sahafariense reminds C. ludiifolium , which has unridged fruits and larger leaves.

Paratypi. – MADAGASCAR. Prov. Antsiranana: Reg. DIANA, forêt d’Analafondro , au pied SE du plateau de Sahafary (bassin inférieur du Rodo), 27.XII.1963, fl., Service Forestier 23087 ( G, P, TEF) ; ibid. loco, 7.II.1966, fl., Service Forestier 24517 ( G, P, TEF) ; forêt de Sahafary (bassin de la Saharenena) , 7.II.1966, fl., Service Forestier 24487 ( G, P, TEF) ; Ambolobozobe , Ambovomavo , à 1 km W du village d’Ambolobozobe, 12°31’13”S 49°31’21”E, 24.XI.2007, fl., Rakotonandrasana 1207 ( CNARP, G, MO, P, TAN).

Figures

Fig. 4. - Capurodendron sahafariense L. Gaut. & Naciri. A. Longitudinal section of flower; B. Flower; C. Corolla opened seen from inside; D. Corolla opened seen from outside; E. Brachyblast with leaves and post-anthesis flower;F. Branch with flowers and fruit; G. Fruit; H. Transverse section of ovary. [Drawings: G. Loza]

Fig. 5. - Field photograph of the type collection of Capurodendron sahafariense L. Gaut. & Naciri. [Photo: F. Ratovoson]

Fig. 3. - Known distribution of (A-B) Capurodendron sahafariense L. Gaut. & Naciri (green), (A, C) C. schatzii L. Gaut. & Naciri (pink), and (A, D) C. nanophyllum L. Gaut. & Naciri (blue). Limits of protected areas in yellow. [Google Earth Images. Copyright 2018 DigitalGlobe. Reproduced per attribution guidelines]