Beguea Capuron

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 : 46-47

Beguea Capuron

in Mém. Mus. Natl. Hist. Nat., B, Bot. 19: 105. 1969.

Typus: Beguea apetala Capuron.

Dioecious small to large trees with simple or rarely stellatefasciculate indument. Leaves alternate, trifoliolate or paripinnately compound with 4-30 alternate to subopposite, entire leaflets, the rachis usually extending slightly beyond the terminal leaflet giving the impression of an aborted leaflet; pseudostipules absent. Inflorescences axillary, sometimes borne on stems below the leaves (ramiflorous), long racemose. Flowers actinomorphic; calyx united basally, (5-)6-7(-8)-lobed; petals absent; disc cushion-shaped, the margin sinuate; stamens 6-8(-10), filaments long, slender, anthers ovate to oblong, laterally dehiscent; staminodia in female flowers resembling short stamens; ovary 3-locular, style longer than the ovary, dividing apically into 3 distinct stigmas, ovule 1 per locule; pistillode in male flowers minute. Fruit indehiscent, globose to obovoid, 1-seeded, dry to somewhat fleshy or woody, crowned by the apiculate remnant of the style; seed surrounded by a translucent, fleshy arillode, the hilar scar basal, the cotyledons highly ruminate.

Notes. – A genus of ten species, occurring in humid and subhumid forest, rarely in dry forest. The genus name honors the French botanist Louis H. Bégué, who founded the Service Forestier collection series in Madagascar.

Key to the species of Beguea

1. Apex of leaflets retuse to deeply emarginate; fruit with mesocarp 3-4.7 mm thick; Andohahela PN......... 3. B. australis

1a. Apex of leaflets rounded to acute or acuminate; fruit with mesocarp (when known) less than 2 mm thick ............. 2

2. Petiole and leaf rachis covered with tufts of very short golden stellate-fasciculate trichomes............................. 3

2a. Petiole and leaf rachis glabrous or with persistent indument of simple trichomes.............................................. 4

3. Apex of leaflets acute to acuminate and short-mucronate, the lamina densely punctate above, the margin slightly revolute; inflorescences unbranched........ 7. B. galokensis

3a. Apex of leaflets rounded, not mucronate, the lamina not punctate above, the margin strongly revolute; inflorescences sometimes branched.............. 4. B. betamponensis

4. Petiole and leaf rachis with dense persistent indument ... 5

4a. Petiole and leaf rachis glabrous or initially with sparse indument, then glabrescent ........................................... 9

5. Leaflets conduplicate, usually folded along the midvein in pressed material............................................................. 6

5a. Leaflets flat in pressed material..................................... 7

6. Leaflets 3-14, the base markedly asymmetrical, the margins usually strongly revolute, secondary veins 8-15 per side; widespread, Manakara S to Farafangana...... 2. B. apetala

6a. Leaflets 4-6, the base symmetrical, the margins flat and minutely thickened but not revolute, secondary veins 7-10 per side; Montagne des Français................. 6. B. borealis

7. Leaflets 6-8, the apex distinctly acuminate, the acumen acute; pedicels c. 1 mm long; anthers 2.2-2.5 mm long; Ankerana............................................. 1. B. ankeranensis

7a. Leaflets 7-16, the apex acute or acuminate, the acumen rounded to irregularly or slightly retuse; pedicels 2.5-4 mm long; anthers c. 1 mm long .......................................... 8

8. Leaflets with secondary veins emerging at a 45̊ angle to the midvein; inflorescence densely light reddish chocolate tomentose; pedicels slender, 0.2-0.5 mm in diam. in flower, sparsely light chocolate tomentulose, 0.9-1 mm in diam. in fruit, glabrous; sepals c. 0.5 mm long; fruit 1.7-1.8 cm long, c. 1.2 cm in diam., ellipsoid to obovoid; Lokobe PA ............................................................ 5. B. birkinshawii

8a. Leaflets with secondary veins emerging at a 25̊ angle to the midvein; inflorescence densely ferruginous tomentose; pedicels stout, 0.7-0.9 mm in diam. in flower, densely ferruginous tomentose, 1.3-1.5 mm in diam. in fruit; sepals c. 1.5 mm long; fruit 2.3-2.8 cm in diam., spheroid; Andohahela, Ranomafana and “Corridor forestier Marojejy- Anjanaharibe Sud-Tsaratanana Nord” .............. 9. B. turkii

9. Leaflets with a flat margin; calyx glabrous; Tsaratanana PA ................................................... 8. B. tsaratananensis

9a. Leaflets with a revolute margin; calyx sparsely puberulous outside; widespread, Marojejy PA S to Bemangidy (N of Tolagnaro)................................................ 10. B. vulgaris