Blackwellia thuarsiana Tul. in Ann. Sci. Nat., Bot. ser. 4, 8: 60–61. 1857 A revision of the Malagasy species of Homalium sect. Blackwellia (Salicaceae) Applequist, Wendy L. Candollea 2018 2018-11-05 73 2 221 244 (Tul.) Baill. Baill. Tul. [839,1234,1675,1700] Magnoliopsida Salicaceae Homalium Plantae Malpighiales 19 240 Tracheophyta species thuarsianum   ≡   Blackwellia thuarsianaTul.in Ann. Sci. Nat., Bot. ser. 4, 8: 60–61. 1857.     Holotypus: MADAGASCAR: sine loco,s.d., fl.,  du PetitThouarss.n. ( P[ P04679701]!;  isotype: L[ L0011030] image seen).   Treeto 20 m, 41 cmdbh; young twigs glabrous. Leavesoblanceolate to obovate (oblong-oblanceolate, elliptical), (2.8 –)3.5 – 7.8(– 10) × (1.2 –)1.6 – 3.8(– 5.2) cm; petiole (0 –)2– 5(–6) mm; base cuneate to convex; apex rounded to somewhat obtuse or acute with rounded apex (shallowly emarginate, rounded-cuspidate); margins entire or subentire, sometimes revolute, occasionally slightly repand, with glands absent or few and sunk in margins; adaxial surface drying grayish to dark (greenish) brown, abaxial surface brown. Inflorescencespaniculate usually with well-developed branches, lateral (pseudoterminal), (4–)6.7–17(–20) cm, moderately to densely pubescent with fine white, usually erect hairs, to short-pilose; flowers pedicellate with pedicels 1–2.7 mm; bracts ovate to broadly elliptical (linear), (0.8–)1.5– 2.5 (seldom foliose, to 22 mm). Flowers7–9-merous; calyx tube subcylindrical with rounded base, pubescent with erect white hairs to pilose; sepals ligulate with acute apex, 1.5–4.2 mm; petals ligulate with acute apex, 1.6–4.5 mm; sepals and petals variable in color, greenish-white to yellowish, cream or beige, pink to red or purple probably in fruit, accrescent, longer than calyx tube, almost always ascending (some flowers spreading at anthesis, apparently returning to ascending in fruit), ciliate with hairs very long near apex, abaxial surface appressed-pubescent (rarely sparsely pilose), adaxial surface sparsely pilose; sepal glands sparsely pilose to sparsely pubescent; filaments 0.8– 1.7 mm, pilose; ovary sparsely to moderately pilose; styles (4)5, (0.6–) 0.8–1.3 mm, pilose at base.   Vernacular names and uses.– “Hazobato” (Service Forestier 2875);“Hazombato” (Lehavana & Zackarie 711, Noyes et al. 960, Rabevohitra et al. 4370, 4610, 4864, 4970, Réserves Naturelles 10340, Service Forestier 4603, 5861, 8314, 9525, 15701, 19526);“Hazombato à g[randes] f[euilles]” (Service Forestier 15701);“Hazombato à p[etites] f[euilles]” (Service Forestier 15172);“Hazombato-mena à p[etites] f [euilles]” (Service Forestier 15702);“Hazondrano-fotsy” (Service Forestier 15704);“Maraokoditra” (Service Forestier 14228);“Tsitakonala” (Service Forestier 4153).  Wood of  H. thuarsianumis used for construction (Service Forestier 19526).   Distribution, ecology and conservation status. – Homalium thuarsianumis native to littoral and sublittoral forests along the eastern coast of Madagascar; it is reported on sand. One specimen (Antilahimena & Felix 7756)was collected at 1053 maltitude, geographically relatively close to the species’ range but far outside its normal altitude range; this specimen cannot be excluded from the species by morphology. Though the habitat is fragmented and highly threatened, this species is relatively widely distributed and occurs in the protected areas of Tampolo, Soanierana-Ivongo, Nosy Mangabe, and Masoala. Therefore its conservation status is estimated as “Least Concern” [LC].   Notes. – Homalium thuarsianumis the most widespread and common of three species with pubescent sepal glands and usually well-developed paniculate inflorescences, the other two being the newly described  H. fortunatiiand  H. martialii. All three share other features in common, including often relatively large bracts, 7–9-merous flowers, and sepals and petals that are usually pubescent on the abaxial surface (in  H. thuarsianum, occasionally sparsely pilose) but somewhat pilose to villous on the adaxial surface. They are all native to low-altitude eastern humid forests. This author considers it reasonable to presume that they are a natural group. The distinctions between  H. thuarsianumand the other two species of this group are described under those species. Flowers are visited by bees (Lehavana et al. 54, Ludovic & Rakotoarivony 241).   Selected material examined.–   MADAGASCAR. Prov. Fianarantsoa: Fkt. Ambahy, forêt d’Andohan’I Martin, 20°48'07"S 48°28'56"E,  22 m,  13.XI.2003, fl.,  Rabehevitraet al. 749( MO, P);  Fkt. Ambahy, 20°46'15"S 48°28'48"E,  21.III.2003, fl.,  Rabevohitraet al. 4610( MO, P);  Entre Vohipeno et la mer,  VII.1954, fl.,  Service Forestier9221( P);  Ankijy, Vatomasina, Vohipeno,  13.IX.1956, fl.,  Service Forestier14228( P);  Ankazondratana, Nosy Varika,  30.V.1958, fl.,  Service Forestier19526( P[2 sheets]).  Prov. Toamasina: Brickaville, fkt. Ambodilendemy, Ankerana, 18°24'58"S 48°47'21"E,  1053 m,  23.III.2011, fl.,  Antilahimena& Felix7756( MO, P);  Mananara,  28.IX.1920, fl. & fr.,  Decary63( P);  Ambila-Lemaitso, 18°49'S 49°09'E,  2–5 m,  15.XI.1989, fl. & fr.,  Keating& Miller2261( MO, P);  Tampolo, 17°17'16"S 49°24'30"E,  16 m,  14.IV.2004, fl. & fr.,  Lehavanaet al. 54( MO, P);  Fkt. Tanambao Ambodimanga, près du gite, 16°47'S 49°43'E,  27.V.2010, fr.,  Lehavana& Zackarie711( MO);  Île Sainte-Marie, Lokintsy, forêt d’Ambohidena on NE coast, 16°51'11"S 49°57'10"E,  10 m,  13.V.2003, fr.,  McPhersonet al. 18913( MO, P);   9.4 kmW of Mahavelona village( Foulpointe), 17°38'S 49°30'E,  10 m,  28.II.1992,  Noyeset al. 960( MO);  Fkt. Ambohidena, forêt d’Ambohidena, 16°51'05"S 49°57'13"E,  10 m,  10.X.2003, fl.,  Rabehevitraet al. 654( MO, P);  Cne rurale Manompana, Forêt Antanambao-Ambodimanga, 16°45'40"S 49°42'35"E,  1.II.2003, fl.,  Rabevohitraet al. 4370( MO, P);  Andranokoditra, Ankanin’ny nofy, forêt de Vohibola, 18°35'42"S 49°14'02"E,  10.II.2003, fl.,  Rabevohitraet al. 4413( MO, P);  Soanierana-Ivongo, Andrangazaha, 16°52'02"S 49°40'52"E,  29.1.2004, fl.,  Rabevohitra& Rakotomamonjy4864( MO, P);  Forêt au NW de Tanambao, 16°45'12"S 49°42'56"E,  31.I.2004, fr.,  Rabevohitraet al. 4970( MO, P);  Fkt. Ambohidena, forêt d’Ambohidena, 16°51'11"S 49°57'18"E,  18.II.2004, fl.,  Rabevohitraet al.5016( MO, P);  Tampini,  X.1924, fl. & fr.,  Réserves Naturelles( Dumazer) s.n.( P);  RN II[ Masoala], Ambohitralalana, district Antalaha,  16.II.1954, fr.,  Réserves Naturelles6620( P);  Soanierana-Ivongo,  18.V.1959, fl. & fr.,  Réserves Naturelles10340( P);  Nosy Mangabe RS  4–5 kmS of Maroantsetra, 15°30'S 49°46'E,  0–330 m,  21.II.1992, fr.,  Schatzet al. 3243( MO, P);  Gare d’Ambila-Lemaitso,  28.VIII.1951, fl. & fr.,  Service Forestier4153( P);  Antetezana, Tamatave,  28.XII.1951, fl. & fr.,  Service Forestier4603( P);  Ambila-Lemaitso,  10.X.1953, fl.,  Service Forestier5861( P);  S de Tenina, S de Rantabe,  IV.1954, fl. & fr.,  Service Forestier9168( MO, P);  Tampolo, Fénérive,  29.VIII.1955, fl.,  Service Forestier15172( MO, P);  Tampolo, Fénérive,  22.II.1956, fl.,  Service Forestier15701( MO, P);  Île Sainte-Marie, forêt d’Ampaniny,  17.V.1969, fr.,  Service Forestier28858( P[2 sheets]). 3470313353 P du Petit- Thouars Madagascar MADAGASCAR 19 240 P04679701 1 holotype 3470313360 L 19 240 L0011030 1 isotype 3470313409 2003-11-13 MO, P Rabehevitra Madagascar Prov. 22 -20.801943 Fianarantsoa 21 48.482224 Fkt. Ambahy 20 241 1 Fianarantsoa 3470313354 2003-03-21 MO, P Rabevohitra Madagascar -20.770834 Fkt. Ambahy 21 48.48 20 241 1 3470313384 1954-07 P Service Forestier Madagascar Entre Vohipeno et la mer 20 241 1 3470313431 1956-09-13 P Service Forestier Madagascar Ankijy Vohipeno Vatomasina 20 241 1 3470313521 1958-05-30 P Service Forestier Madagascar Nosy Varika Ankazondratana 20 241 1 3470313352 2011-03-23 MO, P Antilahimena & Felix Madagascar Prov. 1053 -18.416111 Toamasina 21 48.789165 Brickaville 20 241 1 Toamasina 3470313480 1920-09-28 P Decary Madagascar Mananara 20 241 1 3470313331 1989-11-15 MO, P Keating & Miller Madagascar 4 -18.816668 Ambila-Lemaitso 1274 49.15 20 241 1 3470313329 2004-04-14 MO, P Lehavana Madagascar 16 -17.287777 Tampolo 21 49.408337 20 241 1 3470313385 2010-05-27 MO Lehavana & Zackarie Madagascar -16.783333 Fkt. Tanambao Ambodimanga 1281 49.716667 20 241 1 3470313573 2003-05-13 MO, P McPherson Madagascar Ile Sainte-Marie 10 -16.853056 Lokintsy 21 49.952778 Lokintsy 20 241 1 3470313398 1992-02-28 MO Noyes Madagascar 10 -17.633333 Foulpointe 1278 49.5 20 241 1 3470313493 2003-10-10 MO, P Rabehevitra Madagascar 10 -16.851389 Fkt. Ambohidena 21 49.953613 Fkt. Ambohidena 20 241 1 3470313525 2003-02-01 MO, P Rabevohitra Madagascar Cne -16.76111 Cne rurale Manompana 21 49.709724 Manompana 20 241 1 3470313363 2003-02-10 MO, P Rabevohitra Madagascar Andranokoditra -18.595001 Andranokoditra 21 49.23389 Ankanin'ny 20 241 1 3470313390 2004-01-29 MO, P Rabevohitra & Rakotomamonjy Madagascar -16.867222 Andrangazaha 21 49.681114 Soanierana-Ivongo 20 241 1 3470313375 2004-01-31 MO, P Rabevohitra Madagascar -16.753334 Foret au NW de Tanambao 21 49.715557 20 241 1 3470313514 2004-02-18 MO, P Rabevohitra Madagascar -16.853056 Fkt. Ambohidena 21 49.955 Fkt. Ambohidena 20 241 1 3470313488 1924-10 P Reserves Naturelles & Dumazer Madagascar Tampini 20 241 1 3470313476 1954-02-16 P Reserves Naturelles Madagascar RN II Ambohitralalana 20 241 1 3470313436 [860,1421,1631,1651] 1959-05-18 P Reserves Naturelles Madagascar Soanierana-Ivongo 20 241 1 3470313556 1992-02-21 MO, P Nosy Mangabe RS & Schatz Madagascar 165 -15.5 4 - 5 km S of Maroantsetra 1284 49.766666 20 241 1 3470313439 1951-08-28 P Service Forestier Madagascar Gare d'Ambila-Lemaitso 20 241 1 3470313490 1951-12-28 P Service Forestier Madagascar Tamatave Antetezana 20 241 1 3470313520 [982,1469,1737,1758] 1953-10-10 P Service Forestier Madagascar Ambila-Lemaitso 20 241 1 3470313550 [824,1469,1764,1785] 1954-04 MO, P Service Forestier Madagascar S de Tenina 20 241 1 3470313526 [824,1386,1791,1811] 1955-08-29 MO, P Service Forestier Madagascar Fenerive Tampolo 20 241 1 3470313503 1956-02-22 MO, P Service Forestier Madagascar Fenerive Tampolo 20 241 1 3470313552 1969-05-17 P Service Forestier Madagascar foret d'Ampaniny Ile Sainte-Marie 20 241 1