Uapaca ferruginea Baillon

Mcpherson, Gordon, 2011, A review of Madagascan Uapaca (Euphorbiaceae s. l.), Adansonia (3) 33 (2), pp. 221-231 : 226-228

5. Uapaca ferruginea Baillon ( Figs 1 ; 2 )

Étude générale du groupe des Euphorbiacées: 596

(1858).

Uapaca clusioides Baker , Journal of the Linnean Society , Botany 21: 441 (1884). — Type: Madagascar, Central Madagasacar, s.d., fl. ♂, Baron 2546 (iso-, P [sheet P00298669 ]).

Uapaca ferruginea var. carnotiana Leandri, Mémoires de l’Institut scientifique de Madagascar, Série B, Biologie végétale 8: 257 (1957). — Type: Madagascar, Prov. Fianarantsoa, Ambodivanana, près de Fort-Carnot, 800 m alt., 15.VII.1954, fr., Service forestier 14392 (holo-, P [sheet P00539630 ]) .

TYPUS. — Madagascar. Forêt de Ravinatsara , Manambo , Sainte Marie de Madagascar, IX.1850, fr., Boivin s.n. (lectotype, P [sheet 00298671], here designated).

REPRESENTATIVE MATERIAL EXAMINED. — Madagascar. Prov. Antsiranana, Ambato , 13°26’42”S, 048°33’18”E, 21.XI.1996, Antilahimena 322 ( MO, P) . — Manantenina , 14°26’00”S, 049°45’42”E, 750 m, 21.XI.1996, Messmer 254 ( G, MO, P) . — Masiaposa , 14°38’S, 049°41’E, 26.IV.1967, Service forestier 27798 ( G, K, MO, P) . — Toamasina, Anjiahely , 15°25’01”S, 049°30’39”E, 420 m, 23. XII.2002, Antilahimena 1578 ( MO, P) . — Entre Sahamalaza et Vohilava , 15°37’S, 049°30’E, 500 m, 9.III.1954, Service forestier 9120 ( K, MO, P) . — Antanambao-Ambodimanga , 16°46’06”S, 049°42’22”E, 16. VI.2003, Razakamalala 489 ( MO, P, TEF) . — Ambohidena forest , 16°51’11”S, 049°57’10”E, 10 m, 14. V.2003, Rabenantoandro 1461 ( MO, P, TEF) . — Zahamena , 17°38’S, 049°29’E, 0-100 m, 23. I.1986, Dorr 4618 ( MO, P) . — Eod. loc., 17°39’07”S, 048°58’14”E, 550-600 m, 21.X.2002, Andrianjafy 294 ( MO, P, TEF) . — Mantadia , 18°55’S, 048°25’E, 950-1150 m, 7.XI.1994, McPherson 16532 ( MO, P, TEF) .

DESCRIPTION

Trees 5-15 m tall; dbh 13-45 cm; stilt roots present; leaf-bearing twigs 7-15 mm in diameter, solid or hollow, coated with glossy exudate. Leaf blades obovate, elliptic, or suboblong, (12-)15-25(-28) cm long, (5.5-)9-14(-16) cm wide; base cuneate to obtuse, attenuate into petiole, apex obtuse; secondary veins 6-8(-9) on each side of the midrib; tertiary venation scalariform or nearly so, evident to somewhat obscure or nearly invisible, petiole (2.0-)2.5-6(-8) cm. Staminate peduncles 1.5-7.5 cm long; petaloid bracts c. 8 in number, 7-13 mm × 5-8 mm, ciliate, flowering head 7-8 mm in diameter excluding the exserted stamens; staminodes present; pistillode densely pubescent on distal surface. Pistillate peduncles (1.0-)2-4(-4.5) cm long, typically coated with exudate; calyx in flower c. 4 mm in diameter, coated with glossy exudate, pubescent or apparently sometimes glabrous; calyx in fruit 1-2 mm high, (3.5-)4.5-8(-9) mm in diameter, undulate or slightly lobed, glossy coating usually persistent, indument typically persistent and visible at fruiting time; fruit 15-20(-25) mm long, rounded or pointed at tip, sometimes drying with marked ridges while immature, usually coated with glossy exudate, yellowish or reddish at maturity.

DISTRIBUTION

Eastern and northern forests at lower and middle elevations (5-950 m).

REMARKS

Two forms of fruit seem to exist in this species.Most fruiting specimens bear essentially unridged (although immature) fruit, but a few exhibit a strongly ridged (also immature) fruit. All but two of the latter sort are also unusual in sharing an apparently glabrous calyx and all were collected in the general region of the Bay of Antongil. However, Boivin s.n. (type of the species) and Service forestier 28805, both from Île Sainte Marie, combine a ridged fruit with a calyx bearing the indument usual in the species. Leandri (1958) recognized U. ferruginea var. carnotiana as the name for the sort with the unridged fruit.

Typical specimens are marked by their stout leafy branches, large leaves with scalariform venation, and long peduncles. The species can be confused with U. louvelii if no large leaves or long peduncles are present; however, the copious indument typically persistent and evident on fruiting calyces will often make identification possible. Alternatively, the form with partly collapsed, and therefore conspicuously ridged, fruit is easily recognized. Also similar is U. amplifolia , but that species has smaller staminate heads and broader leaf blades and is restricted to the NW. Further collecting and study may, nevertheless, lead to the inclusion of U. amplifolia as a subspecies of U. ferruginea .

Two specimens (Schatz 2312 and 2950) from Nosy Mangabe in the Bay of Antongil are tentatively placed here, although their short petioles and the pistillate specimen’s large fruit (28 mm long) make them somewhat unusual.

Figures

FIG. 1. — Staminate specimen of Uapaca ferruginea Baill. showing capitate inflorescences (McPherson 14844).

FIG. 2. — A, staminate flower of Uapaca ferruginea (SEM photo), side view with calyx dissected open, showing stamens and staminodes (2 of each in central foreground) and pistillode (in background) (McPherson 14844); B, individual staminode of Uapaca louvelii Denis (SEM photo) (Koopman 131). Scale bars: A, 1 mm; B, 0.5 mm.