Uapaca amplifolia Denis

Mcpherson, Gordon, 2011, A review of Madagascan Uapaca (Euphorbiaceae s. l.), Adansonia (3) 33 (2), pp. 221-231 : 224

2. Uapaca amplifolia Denis

Archives de Botanique, Bulletin mensuel, Caen 1: 224 (1927). Uapaca rivularis Denis, Archives de Botanique , Bulletin

mensuel, Caen 1: 225 (1927). — Type: Madagascar ,

Domaine de l’Ouest, bord du Mananzovo à Tsaratan-

ana, s.d. ft., Perrier de la Bâthie 4632 (lecto-, P [sheet

P00132898 ], here designated ). TYPUS. — Madagascar. Prov. Antsiranana, forêts du massif de Manongarivo au-dessous de 500 m alt., sur les grès liasiques exclusivement , VI.1909, fl. ♂, Perrier de la Bâthie 11590 (lecto-, P [sheet P00132876 ], here designated). REPRESENTATIVE MATERIAL EXAMINED. — Madagascar. Prov. Antsiranana, Anjahana , 13°21’15”S, 049°11’01”E, 118 m, 07. VI.2005, Hong-Wa 314 ( MO, P, TAN). — Tsaratanana RNI, 13°52’33”S, 048°48’44”E, 700 m, 26.III.2000 , Antilahimena 422 ( MO, P). — Antsahabe , 13°47’22”S, 048°13’50”E, 516 m, 11.XI.2001 , Antilahimena 779 ( MO, P, TAN). — Manongarivo , 14°04’S, 048°17’E, 270 m, 11. VI.1994, Gautier 2299 ( G, MO, P). — Eod. loc., 300 m, 5.IX.1997 , Gautier 3251 ( G, MO, P). — Manongarivo , 14°02’S, 048°19’E, 800-1100 m, 7-12. XII.1992, Malcomber 1958 ( MO, P, TAN). — Prov. Mahajanga, Irony-Bealanana (c. 14°45’S, 048°22’E), 300-500 m, 21. VI.1953, Service forestier 7440 ( MO, P) .

DESCRIPTION

Tree 8-20m; stilt roots reportedly sometimes absent or reduced; leaf-bearing twigs 3-7(-10) mm in diameter, solid or hollow. Leaf blades obovate, (8-) 11-24 cm long, (4.5-)7.0- 18 cm wide (blade width at least 0.6 × length for all but the smallest leaves), base broadly cuneate to obtuse, apex obtuse, secondary veins 5-8(-9) on each side of the midrib, sharply raised and readily visible, tertiary venation subscalariform, both it and the higher venation visible abaxially; petiole 2.0-4.0(-5.5) cm long. Staminate peduncles 1-3.3 cm long; petaloid bracts c. 10 in number, c. 8 mm long, c. 5 mm wide; flowering heads 4-5 mm in diameter excluding the exserted stamens; calyx, at least in part, of free or nearly free narrow segments; staminodes apparently infrequent, but present in at least some flowers; pistillode somewhat pubescent on distal surface.Pistillate peduncles 0.5-3 cm long; petaloid bracts 3-10 in number, 5-11 mm long, c. 5 mm wide; calyx in flower 2.5-3 mm in diameter, often broadly lobed, glabrous or somewhat pubescent abaxially, pubescent adaxially at the junction with the axis, the hairs often somewhat exserted beyond the sinuses, calyx in immature fruit up to 5.5 mm in diameter, the calyx wall remaining merely c. 1 mm high; ovary typically coated with exudate, pubescent at least distally, immature fruit c. 2 cm long, pubescent distally or glabrescent.

DISTRIBUTION

Northwestern Madagascar at elevations of 120- 1200 m.

REMARKS

Distinguished by its typically broad leaf, its short, abaxially glabrous or nearly glabrous pistillate calyx that is adaxially pubescent at its junction with the floral axis, and its distally pubescent ovary. Resembling U. ferruginea but with wider leaves typically, smaller staminate heads and a northwestern distribution.