A revision of Homalium sect. Rhodonisa (Salicaceae) endemic to Madagascar Applequist, Wendy L. Candollea 2020 2020-10-29 75 2 245 268 7WN2S Appleq. Appleq. 2020 [151,507,1665,1690] Magnoliopsida Salicaceae Homalium Plantae Malpighiales 11 256 Tracheophyta species megaphyllum sp. nov.     Holotypus: MADAGASCAR. Reg. DIANA[Prov. Antsiranana]: Behefaka, Anjahana, 13°21'32"S 49°10'10"E,  123 m,  5.VI.2005, fr.,  Hong-Wa et al.296( MO-6175072!; iso-: G[ G00341931] image seen, P[ P04734804]!, TAN).    Homalium megaphyllum Appleq.differs from H. leucophloeum (Tul.) Baill.in its much larger, usually elliptical to oblongelliptical leaves with usually subentire margins, inflorescences often cauliflorous on twigs below leaves, and flowers often short-pedicellate.   Treeto 20 mtall, 30 cmdbh; twigs dark brown, glabrous. Leaveselliptical to oblong-elliptical (narrowly elliptical, ovate), 13– 35 × (5–) 5.7 – 11.5 cm, relatively thin-textured (moderately thick); margin subentire, often slightly undulate; base rounded to convex or somewhat oblique; apex cuspidate to short-acuminate or acute (rounded, emarginate); both surfaces glabrous, drying brown or green abaxially, dark brown to blackish (seldom greenish) adaxially; secondary veins slightly prominent; petiole sometimes red, (11–)13–20(–29) mm, glabrous. Inflorescencesoften mostly cauliflorous on twigs below leaves, racemose, (4.5–)8–15(– 23) cm; peduncle 0.3–1.3(– 3) cm; rachis glabrous (short-pubescent); flowers (1)2 –4 per node; pedicels 0.5–1 mm, short-pubescent, or flowers sessile. Flowers4-merous, white; sepals oblong to somewhat obovate, 1.3–3.5 mm, glabrous except margins short-ciliate; sepal glands suborbicular, 0.5–0.6 × 0.5 mm; calyx cup sparsely pubescent; petals narrowly obovate, 3.5– 7 mm, moderately accrescent, glabrous, margins not ciliate; filaments 0.6–0.9 mm; anthers transversely elliptical, c. 0.3 mmhigh.   Etymology. –  Homalium megaphyllumis so named for its exceptionally large leaves.   Vernacular names.– “Hazoadala” ( Antilahimena et al. 370, 463, Gautier & Be 2905, Réserves Naturelles 1449, 2954, 4362, Service Forestier 7690, 9293, 13388); “Hazoanolalana” ( Service Forestier 3054).   Distribution, ecology and conservation status. – Homalium megaphyllumis confined to northern Madagascar, primarily the DIANA region ( Fig. 2). It is frequently reported to occur along the banks of rivers or streams, including seasonal temporary streams, and once to grow in deep red soil. It has been collected in degraded, or secondary, savoka forests.  More than ten probably distinct populations have been collected, and it occurs in the protected areas of Manongarivo, Tsaratanana and Lokobe. Its conservation status is tentatively assessed as “Least Concern” [LC].   Notes. – Homalium megaphyllumis certainly more closely related to  H. leucophloeumand  H. bailloniithan to  H. albiflorum s.str., as evidenced by its 4-merous flowers with glabrous sepal and petal surfaces. It has a much larger maximum leaf size than any other species of the section, and is also unique in having most inflorescences borne proximally on mature twigs, rather than in leaf axils.     Paratypi.–  MADAGASCAR. Reg. DIANA[Prov. Antsiranana]: Ambato classified forest, river Bevoay, trail to Ankarefo, 13°28'03"S 48°32'22"E,  0–100 m,  28.V.1998, fl.,  Antilahimena et al. 370( G, K, MO, P);  Tsaratanana Massif, Antsahabe-Mandrizavona, 13°43'12"S–13°48'S 48°39'25"E–48°45'E,  150–750 m,  12.IV.2000, fl.,  Antilahimena et al. 463( BR, G, K, MO, P); env. de Maromandia( Kapany),  9.IV.1923, fl.,  Decary 1676( G, P);  Besinkara, 14°04'S 48°17'E, ch. d’Ambalafaryà Ambodisakoana,  350 m,  26.III.1996, fl.,  Gautier& Be 2905( G, MO, P);  SW d’Ambilobe,  10 m,  III.1951, fr.,  Humbert& Capuron 25589( P);  Vallée de l’Ifasyen aval d’Anaborano, distr. d’Ambilobe Nord,  50–200 m,  31.III.1951, fr.,  Humbert& Capuron 25880( P); env. de Mt. Bekolosy, massif de Manongarivo,  III.1909, fl. & fr.,  Perrier de la Bâthie 6718( P[2 sheets]); presqu’île d’Ampasindava, 13°46'30"S 48°05'35"E,  215 m,  7.V.2012, fr.,  Rasoanaivo& Tahinarivony 28( MO);  Tsaratanana, rive droite du Sambirano, au delà du village Beangona,  21.V.1948, fr.,  Réserves Naturelles 1449( P[3 sheets]);  Lokobe, Nossi Be,  22.IX.1952, fl.,  Réserves Naturelles 4362( P[2 sheets]);  Andrahibo, Ambanja,  16–30.III.1951, fl.,  Service Forestier 2954( P); entre Ambatobeet [illegible], distr. d’Ambilobe,  12.III.1951, fl.,  Service Forestier 3054( P);  Benavony, Ambanja,  25.III.1954, fr.,  Service Forestier 9293( P);  Manongarivo RS, Anketraka Be, Bas Ambahatra, cours inférieur du bassin-versant de rano Ambahatra( 13°55'16"S, 48°27'47"E),  180 m,  22.VII.1998, fr.,  Wohlhauser& Andrianjaka 60016( G, MO, P).   Reg. Sofia[Prov. Mahajanga]: Analalava, Bekaraka, env.  40 kmS d’Ambanjale long de la RN6, 13°56'09"S 48°12'45"E,  195 m,  21.V.2006, fl.,  Rakotoarisoa& Andriamahay 436( MO);  Ambodisaina, Ambanja,  17.IX.1953, fr.,  Service Forestier 7690( P);  Ampondralava, Antsohihy,  25.IV.1955, fr.,  Service Forestier 13388( P).  Reg. unknown: sine loco,s.d., fr.,  Baron 6224( P). 3469826333 5. VI. 2005 G, P, TAN Hong-Wa et al. Madagascar 123 -13.35889 Anjahana 21 49.169445 Behefaka 11 256 MO-6175072, G00341931, P04734804 1 DIANA holotype 3469826302 1998-05-28 G, K, MO, P Antilahimena et al. Madagascar 50 11 258 -13.4675 Ambato classified forest 21 48.539444 Ankarefo 11 256 370 1 DIANA paratype 3469826357 2000-04-12 BR, G, K, MO, P Antilahimena et al. 450 13 258 -13.8 Tsaratanana Massif 1289 48.75 11 256 463 1 paratype 3469826402 1923-04-09 G, P Decary 13 258 Maromandia Maromandia 13 256 1676 1 paratype 3469826397 1996-03-26 G, MO, P Gautier & Be 350 13 258 -14.066667 Besinkara 1289 48.283333 Besinkara 13 256 2905 1 paratype 3469826422 1951-03 P Humbert & Capuron 10 13 258 d'Ambilobe d'Ambilobe 13 256 25589 1 paratype 3469826328 1951-03-31 P Humbert & Capuron d'Ambilobe Nord 125 13 258 Vallee de l'Ifasy d'Anaborano 13 256 25880 1 paratype 3469826359 1909-03 P Perrier de la Bathie 13 258 Mt. Bekolosy 13 256 6718 1 paratype 3469826409 2012-05-07 MO Rasoanaivo & Tahinarivony 215 13 258 -13.775 d'Ampasindava 21 48.093056 d'Ampasindava 13 256 28 1 paratype 3469826303 1948-05-21 P Reserves Naturelles Beangona 13 258 Sambirano Tsaratanana 13 256 1449 1 paratype 3469826392 1952-09-22 P Reserves Naturelles 13 258 Nossi Be Lokobe 13 256 4362 1 paratype 3469826321 1951-03-16 1951-03-30 1951-03-16 P Service Forestier 13 258 Ambanja Andrahibo 13 256 2954 1 paratype 3469826361 1951-03-12 P Service Forestier 13 258 Ambatobe Ambatobe 13 256 3054 1 d'Ambilobe paratype 3469826433 1954-03-25 P Service Forestier 13 258 Ambanja Benavony 13 256 9293 1 paratype 3469826301 1998-07-22 G, MO, P Wohlhauser & Andrianjaka Anketraka Be 180 13 258 -13.921111 Manongarivo RS 21 48.463055 Bas Ambahatra 13 256 60016 1 paratype 3469826456 2006-05-21 MO Rakotoarisoa & Andriamahay 195 13 258 -13.935833 Bekaraka 21 48.2125 Reg. Sofia 13 256 436 1 Mahajanga paratype 3469826387 1953-09-17 P Service Forestier 13 258 Ambanja Ambodisaina 13 256 7690 1 paratype 3469826309 1955-04-25 P Service Forestier 13 258 Antsohihy Ampondralava 13 256 13388 1 paratype 3469826307 [204,622,864,883] P Baron 13 258 13 256 6224 1 paratype