Beguea turkii G.E. Schatz, Gereau & Lowry

George E. Schatz, Roy E. Gereau & Porter P. Lowry Ii, 2017, A revision of the endemic Malagasy genus Beguea (Sapindaceae), Candollea 72 (1), pp. 45-65 : 61-63

9. Beguea turkii G.E. Schatz, Gereau & Lowry , spec. nova

( Fig. 2 C, 11).

Typus: MADAGASCAR. Prov. Fianarantsoa: Vatovavy- Fitovinany Region, Ranomafana National Park , parcelle 3, S of National Road 25 at 7 km W of Ranomafana, Vatoharanana trail system , 21̊17’S 47̊26’E, 1100-1250 m, 3.XII.1992, fl., Turk & Solo 192 (holo-: MO-05035874! ; iso-: P [P00214653]!, TAN!).

Haec species a congeneris caulibus petiolis folii rhachide petiolulis folioli costa inflorescentiae axe et pedicellis indumento ferrugineo dense tomentosis atque pedicellis crassis distinguiter.

Trees 10-17 m tall, bole to 17 cm diam.; stems densely ferruginous tomentose, glabrescent. Petioles 2.3-5.5 cm, densely ferruginous tomentose. Leaves with 7-16 subopposite to alternate leaflets; rachis 2.8-12.2 cm, not keeled, densely ferruginous tomentose; petiolule 1-3 mm, swollen, densely ferruginous tomentose; leaflet blade 1.8-8.1 × 0.8-2.3 cm, lanceolate to narrowly oblong, chartaceous to subcoriaceous, flat in pressed material, glabrous above, initially ferruginous tomentose below, glabrescent, base markedly asymmetrical, margins slightly revolute, apex acuminate, the acumen rounded to sometimes slightly retuse, midvein raised above, initially densely ferruginous tomentose, glabrescent, raised below, persistently densely ferruginous tomentose, secondary veins 14-21 per side, ascending at an angle of 25º from the midvein, slightly raised above and below, tertiary veins finely reticulate, slightly raised above and below. Inflorescence axis 8-15 cm long, 1.5-2.5 mm in diam., unbranched, densely ferruginous tomentose; bracts 0.7-1 mm, triangular, adaxially concave; pedicels 3-4 mm, 0.7-0.9 mm in diam., densely ferruginous tomentose. Male flowers with a cupulate, 5- or 6-lobed calyx, the lobes c. 1.5 × 0.5 mm, erect and curved inwards slightly, densely ferruginous tomentose outside, glabrous inside; disc c. 1.5 mm in diam., drying dark, glabrous to sparsely golden granular-farinose; stamens 6-8, filaments 3-4 mm, glabrous, anthers c. 1 × 0.5 mm, ellipsoid. Female flowers not seen. Infructescence 7.5-8.2 cm, c. 2 mm in diam., densely ferruginous tomentose; pedicels 1.3-1.5 mm in diam. in fruit, densely ferruginous tomentose. Fruit spheroid, glabrous, 2.3-2.8 cm in diam., abruptly apiculate, the apiculum c. 1 mm; the fruit wall c. 1 mm thick; seed discoid, 12-14 mm in diam., c. 0.5 cm thick.

Etymology. – The epithet turkii honors Dan Turk, who has significantly advanced our knowledge of the trees of Ranomafana National Park, and who continues to promote the cultivation of indigenous Malagasy trees.

Conservation status. – Beguea turkii has a restricted range size ( Fig. 4 ), with an EOO of 8,550 km2 and an AOO of less than 500 km2. While there may be no current threats at its locations in Andohahela and Ranomafana National Parks, continuing decline in the quality of the habitat from forest exploitation and clearing can be projected at the northern SAVA location southwest of the village of Morafeno along the boundary of the “Corridor forestier Marojejy-Anjanaharibe Sud-Tsaratanana Nord”. Therefore, B. turkii is assigned a preliminary status of “Endangered” [EN B2ab(iii)] using the IUCN Red List Criteria ( IUCN, 2012).

Fig. 11. – Begueo turkii G.E. Schatz, Gereau & Lowry. A. Flowering branch; B. Portion of inflorescence axis; C. Detail of flower at anthesis; D. Infructescence axis with fruits; E. Seed.

[A-C: Turk & Solo 192, MO; D: Rokotomolozo 492, MO] [Drawing: R.L. Andriamiarisoa]

Notes. – Beguea turkii is known from three widely dispersed locations in mid-elevation subhumid forest ( Fig. 4 ). It can be distinguished from B. birkinshawii , the species most similar morphologically, by its stout pedicels (0.7-0.9 mm in diam. in flower, 1.3-1.5 mm in diam. in fruit vs 0.2-0.5 mm in diam. in flower, 0.9-1 mm in diam. in fruit vs), larger sepals (c. 1.5 mm vs c. 0.5 mm long), and larger spheroid fruit (2.3- 2.8 cm in diam vs ellipsoid to obovoid and 1.7-1.8 cm long, c. 1.2 cm in diam) ( Fig. 11 ).

Paratypi. – MADAGASCAR. Prov. Antsiranana: SAVA Region, forêt d’Antsahandroboka , située à env. 10 km au SW du village de Morafeno, sentier d’Antsahandavakanjo vers Antsahabaraoka , 14̊09’26’’S 49̊23’09’’E, 1010 m, 18.II.2007, fl., Rakotovao et al. 3648 ( G, P, MO, TAN). Prov. Fianarantsoa: Vatovavy-Fitovinany Region, Ranomafana NP , parcelle 3 , S of National Road 25 at 7 km W of Ranomafana, Valohoaka trail system , 21̊18’S 47̊26’E, 1100-1250 m, 19-21.XI.1992, fl., Turk, Randrianasolo & Solo 169 ( MO, P, TAN). Prov. Toliara: Anosy Region, RNI #11 Andohahela , Camp 3 , 13.5 km NW d’Eminiminy, 24̊35’04’’S 46̊44’08’’E, 1000-1400 m, 9.XI.1995, fr., Rakotomalaza 492 ( MO, TAN).

Figures

Fig. 2. – Photographs of Begueo Capuron. A. Begueo onkeronensis G. E. Schatz & Lowry; B. Begueo opetolo Capuron; C. Begueo turkii G. E. Schatz, Gereau & Lowry; D. Begueo vulgoris G. E. Schatz, Gereau & Lowry.

Fig. 4. – Geographic distribution of Begueo opetolo Capuron (circles), B. birkinshowii G. E. Schatz, Gereau & Lowry (stars), B. boreolis G. E. Schatz & Lowry (diamond), B. tsorotononensis G. E. Schatz, Gereau & Lowry (squares) and B. turkii G. E. Schatz, Gereau & Lowry (triangles), mapped on the bioclimatic zones of Madagascar (after CORNET, 1974; see SCHATZ, 2000).

Fig. 11. – Begueo turkii G. E. Schatz, Gereau & Lowry. A. Flowering branch; B. Portion of inflorescence axis; C. Detail of flower at anthesis; D. Infructescence axis with fruits; E. Seed. [A-C: Turk & Solo 192, MO; D: Rokotomolozo 492, MO] [Drawing: R. L. Andriamiarisoa]