Uapaca louvelii Denis

Mcpherson, Gordon, 2011, A review of Madagascan Uapaca (Euphorbiaceae s. l.), Adansonia (3) 33 (2), pp. 221-231 : 230

7. Uapaca louvelii Denis ( Fig. 2B )

Archives de Botanique, Bulletin mensuel, Caen 1: 230 (1927).

Uapaca louvelii var. paralia Leandri, Mémoires de l’Institut scientifique de Madagascar, Série B, Biologie végétale 8: 258 (1957). — Type: Madagascar. Prov. Fianarantsoa, région de Mananjary, Marohita, 0-50 m alt., 6. I .1952, fl. ♂, Service forestier 5616 (holo-, P [sheet P00132889 ]) .

TYPUS. — Madagascar. Prov. Toamasina, Tampina, au Sud de Tamatave, forêt littorale, s.d., fr., Perrier de la Bâthie 14909 (lecto-, P [sheet P00132885 ], here designated) . REPRESENTATIVE MATERIAL EXAMINED. — Madagascar. Prov. Antsiranana, Mont Beondroka , 14°24’S, 049°46’E, 1000-1450 m, 17-22.III.1949 , Humbert 23458 ( K, MO, P). — Eod. loc., 14°27’S, 049°47’E, 830-1210 m, 26.X.1989 , Miller 4446 ( MO, P). — Prov. Toamasina, Tanambao , 16°46’07”S, 049°42’39”E, 30. I.2004, Rabevohitra 4887 ( MO, P, TEF). — Île Sainte Marie , 16°51’11”S, 049°57’10”E, 10 m, 13. V.2003, McPherson 18911 ( MO, P, TEF). — Eod. loc., 16°51’11”S, 049°57’18”E, 18.II.2004 , Rabevohitra 5064 ( MO, P, TEF). — Ambila-Lemaitso , 18°49’S, 049°08’E, 0 m, 2.X.1993 , Lewis 715 ( MO, P). — Eod. loc., 18°51’S, 049°08’E, 0-50 m, 29.VIII.1987 , Schatz 1467 ( MO, P). — Antaimby , 20°22’21”S, 048°33’15”E, 13 m, 11. VI.2004, Razakamalala 1368 ( MO, P, TEF) .

DESCRIPTION

Trees 4-15(-25) m; dbh 15-70 cm; stilt roots present; leaf-bearing twigs 4-5(-6) mm in diameter, typically coated with glossy exudate, solid; leaf blades obovate, (3.5-)7.5-15(-17) cm long, (1.5-)2.5-6- (-7.5) cm wide, base cuneate and attenuate into petiole or occasionally obtuse; apex obtuse; secondary veins (4-)6-8(-9), impressed adaxially, slightly raised abaxially, the tertiaries often obscure but scalariform; petiole (0.1-)2-4.5(-5.5) cm long. Staminate peduncles 8-20(-23) mm long; the flower head 5-6 mm in diameter excluding the exserted stamens; stamens 5; staminodes present, pistillode pubescent on distal surface, sometimes densely so. Pistillate peduncles (2-)6-15(-23) mm long; calyx in flower c. 4 mm in diameter, coated with glossy exudate typically and appearing glabrous, but when without this coating usually somewhat pubescent, as is the cushion-like receptacle, in fruit 1-1.5 mm high, 4.5-5.5 mm in diameter, undulate or lobed; mature fruit 15-20 mm long, ovoid, rounded or somewhat pointed apically, often slightly ridged on drying, usually coated with glossy exudate.

DISTRIBUTION

Eastern forests from near sea level up to at least 1000 m.

REMARKS

Typical specimens are coated with a glossy exudate over both the vegetative and reproductive structures, but a more sparingly coated form exists that cannot be convincingly separated from this species on any additional basis. Larger-leaved specimens may be mistaken for U. ferruginea , but the latter’s more evident scalariform venation, typically longer peduncles, and typically more densely pubescent pistillate calyx will usually serve to distinguish the two species, as will the latter’s larger staminate flowering heads. Smaller-leaved specimens might be mistaken for U. densifolia , but that species’ lack of scalariform venation should permit discrimination. Higher elevation forms tend to have shorter petioles.

Figures

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.