Homalium brevipedunculatum Scott-Elliot

Wendy L. Applequist, 2016, Revision of the Malagasy species of Homalium sect. Eumyriantheia Warb. (Salicaceae), Candollea 71 (1), pp. 33-60 : 37-38

2. Homalium brevipedunculatum Scott-Elliot in J. Linn. Soc., Bot. 29: 21. 1891.

Typus: Madagascar. Prov. Toliara: Fort-Dauphin , V.18 ??, post-fl., Scott Elliot 2600 (holo-: K [ K000231468 ] image seen; iso-: P [ P00375087 ]!).

Tree to 20 m tall, 35 cm dbh; large twigs dark gray to gray or dark brown; young twigs grayish to pale brown, glabrous (to sparsely or partially pubescent); stipules narrowly lanceolate or linear, 1.7-2 mm, pubescent. Leaves subopposite to alternate especially proximally; petiole 3-12(-17) mm, glabrous or sparsely (to moderately) pubescent when young; blade obovate (narrowly or broadly obovate, elliptical), (3.7-)5.1-11 × 2.1- 5.8(-6.5) cm; base convex (cuneate, rounded); apex rounded to emarginate; margins usually somewhat revolute, occasionally minutely toothed then with 1-5 glands toward base of leaf, rarely more; abaxial surface sparsely pubescent on midrib (and blade), drying brown; adaxial surface glabrous, drying brown (green). Inflorescences racemose, lateral, sometimes mostly confined to distalmost portion of twigs, 1.5-4(-5.3) cm, densely (to moderately) short-pubescent; peduncle 0.3-0.8 cm, sturdy; pedicel 1-2(-4) mm, densely pubescent; bracts broadly ovate (ovate), (1.4-) 2-3.8 mm, densely pubescent; bracteoles ovate, sometimes apparently absent, 1.5-2.5 mm, densely pubescent. Flowers: sepals (4-)5(-6), greenish-beige to whitish or yellowish, narrowly oblong (oblong-elliptical, oblanceolate) with acute apex, 4.5-7.5 mm, abaxial surface densely to moderately pubescent (to sericeous), often slightly keeled at apex; calyx cup funnelform (becoming cylindrical), densely to moderately pubescent (to sericeous); sepal glands yellow, conspicuously elevated, 0.9-1.3 × 0.9-1.3 mm, the upper surface glabrous and wrinkled, with pubescence underneath on abaxial surface; petals greenish-white to white or yellowish-white, oblanceolate to narrowly obovate with a narrow base, acute to obtuse or rounded apex, 4.5-8.5 × 1.8-3.2 mm, slightly longer than or about equal to sepals, abaxial surface densely pubescent and often shallowly keeled, adaxial surface glabrous or rarely sparsely pubescent; filaments white to yellowish, 2.4-3.8 mm, glabrous; anthers yellow, 0.3-0.4 mm; ovary short-conical, long-pubescent to pilose; styles 3(-4), dark reddish green, 1.5-3.5 mm, basally long-pubescent. Seeds probably 1 per fruit; mature seeds not seen.

Vernacular names. – “Maranikoditra” (Faliniaina et al. 37, Ramison et al. 139); “Rohandriana” (Service Forestier 6610, 7851).

Distribution, ecology and conservation status. – Homalium brevipedunculatum is native to littoral and low-elevation humid forests of southeastern Madagascar; it is reported primarily on sand, but occasionally on laterite. Fewer than ten distinct locations are known, most close to Fort-Dauphin; though these include some protected land, the remainder of its range is subject to ongoing forest loss, justifying a preliminary conservation status assessment of “Vulnerable” [VU B2ab(iii)] following IUCN Red List Categories and Criteria.

Notes. – Homalium brevipedunculatum most closely resembes, and co-occurs in part of its range with H. nobile ; the latter species has sometimes very large leaves, (5.5-)6.5-18 × (3-) 4-9 cm, with at least slight pubescence on the midribs, and petals 3.4-5 mm broad. The other common littoral species with racemose inflorescences and densely pubescent perianth, H. laxiflorum , has broader and on average shorter sepals and petals with rounded apices, with the petals usually well exceeding the sepals; neither petals nor sepals are at all keeled, and their indument, though partly dense, is generally short.

Rabenantoandro et al. 954 from Mahabo (23°10’20”S 47°42’23”E; MO) has flowers like those of H. brevipedunculatum , with narrow petals, and the leaf midribs are virtually glabrous, but the leaves are very large as is typical of H. nobile . Both species are known from Mahabo. It is suggested to be a hybrid between those species.

Additional material examined. – Madagascar. Prov. Fianarantsoa: S of Farafangana, near village of Mahabo , 23°10’51”S 47°42’29”E, 30 m, 5.XI.2001, fl., McPherson & Rabenantoandro 18358 ( MO, P) ; Fkt. Nosy ala, forêt d’Analazaha , 23°10’13”S 47°43’27”E, 22 m, 26.VIII.2003, fl., Rabehevitra et al. 558 ( P). Prov. Toliara: Fort-Dauphin, fl., Cloisel 125 ( P); forêt sur la route de Ste Luce , partie S, 24°46’S 47°09’E, 0-10 m, 23.III.1989, post-fl., Dumetz 631 ( MO, P) ; Fkt. Sainte Luce, 24°46’41”S 47°10’04”E, 17.XII.2000, fl. and post-fl., Faliniaina et al. 37 ( MO) ; Bemangidy forest, ca. 3 km E of Antsotso , along RN 12a, 24°34’05”S 47°12’38”E, 100 m, 10.II.2006, post-fl., Lowry et al. 6756 ( MO, P) ; Ste. Luce region, Manafiafy , 24°47’S 47°10’E, 25 m, 19.X.1989, fl., McPherson et al. 14168 ( MO, P) ; few km NW of Manantenina, forêt d’Analalava , 24°13’S 47°21’E, 40 m, 28.X.1989, fl., McPherson 14274 ( MO, P) ; N of town near village of Ste. Luce ( Manafiafy ), forest NW of village, 24°47’S 47°10’E, 20 m, 16.I.1990, post-fl., McPherson et al. 14808 ( MO, P) ; Taolagnaro , forêt M 7, 24°57’31”S 47°00’02”E, 0-10 m, 6.X.2000, fl., Rabenantoandro et al. 333 ( MO, P) ; Fkt. Sainte Luce, forêt sublittorale de S8, Hova site minier, 24°46’29”S 49°08’57”E, 6 m, 4.XI.2003, fl., Rabenantoandro & Ramisy 1540 ( MO, P) ; Fkt. Sainte Luce, forêt d’Analavinaky , à l’W du village d’Ambandrika, 24°46’30”S 47°09’00”E, 21 m, 24.XI.2009, fl., Rakotovao 4736 ( MO) ; sentier reliant Ampasy et Iaboakoho village, 24°35’57”S 47°09’31”E, 29.XI.2009, fl., Rakotovao et al. 4909 ( MO) ; forêt d’Ambavarano , 24°57’32”S 47°02’07”E, 7 m, 11.XII.2006, fl, Ramison et al. 139 ( MO) ; Ste. Luce, fkt. Manafiafy , forêt de Manafiafy , 24°46’08”S 47°10’14”E, 21 m, 30.XI.2002, fl., Randrianaivo et al. 865 ( MO, P) ; Antsotso, forêt d’Ivohibe, 24°56’46”S 47°19’54”E, 386 m, XI.2005, fl., Razakamalala et al. 2458 ( MO, P) ; Iaboko, Antsotso Avaratra , 24°34’35”S 47°12’28”E, 25 m, 13.XII.2007, fl., Razakamalala et al. 4025 ( MO, P) ; N of Ft. Dauphin on road to Ste. Luce, block S-9 of QUIT-FER, 24°47’S 47°11’E, 15 m, 12.XI.1990, fl., Schatz et al. 2999 ( MO, P) ; Mandena, 19.XII.1952, post-fl., Service Forestier 6610 ( P) ; Mandena, 3.XI.1953, fl., Service Forestier 7851 ( P) ; Vinanibe , à l’W de Fort-Dauphin, 7.XII.1968, fl., Service Forestier 28619 ( P [2 sheets]).