Notes on the genus Ochna L. (Ochnaceae) in Madagascar Author Callmander, Martin, W. Missouri BotanicalGarden, P. O. Box 299, St. Louis, Missouri, 63166 - 0299, U. S. A. and Conservatoire etJardin botaniques de la Ville de Genève, ch. de l’Impératrice 1, case postale 60, 1292 Chambésy, Genève. Switzerland. martin.callmander@mobot.org Author Phillipson, Peter B. Missouri Botanical Garden, P. O. Box 299, St. Louis, Missouri, 63166 - 0299, U. S. A. and Muséum national d’Histoire naturelle, Département Systématique et Evolution, UMR 7205 OSEB, case postale 39, rue Cuvier 57, 75231 Paris, cedex 05, France text Candollea 2012 2012-07-01 67 1 142 144 journal article 3270 10.15553/c2012v671a14 012626c5-792b-45f3-b7e6-16ec61420de8 2235-3658 5789051 Ochna sambiranensis Callm. &Phillipson , nom. nov. Ξ Polythecium macranthum Tiegh. in Ann. Sci. Nat. Bot. ser 8, 16: 370. 1902 . Typus: MADAGASCAR . Prov. Antsiranana: Nosy Be , meeresstrand, VII.1879 , fl., Hildebrandt 3192 ( holo- : P [ P00568727 ]!; iso-: G [ G00353496 ]!, P [ P00568728 , P005 68729]!) . Observations. – This species was first described as Polythecium macranthum Tiegh. , based on a single collection (Hildebrandt 3192) from Nosy Be. The species was placed in synonymy by PERRIER DE LA BATHIE (1941) , along with seven other species of Polythecium described by Van Tieghem, under a very broadly-circumscribed Diporidium ciliatum (Lam.) Kuntze (= Ochna ciliata Lam. ). We have found a number of additional collections also from lowland forests in the Sambirano region of NW Madagascar that are an excellent match for the type collection, mostly modern collections that were not availabletoPerrier de laBâthie. The specimens all possess a distinct suite of characters, and we believe they represent a well-marked species that should now be recognised in the genus Ochna . A new combination in Ochna based on the existing epithet is not possible, because this name already exists for adifferent species ( O. macrantha Baker ,also from Madagascar ). We therefore propose the new name O. sambiranensis for this species. VAN TIEGHEM (1902b: 370) noted the following diagnostic characters for the species: its relatively large leaves with their conspicuously ciliate margins and mucronate apices and itslarge flowersinafew-flowered racemewithahighlycontracted axis, resembling an umbel ( Fig. 1 ).Inaddition we add that O. sambiranensis can be distinguished from O. ciliata to which it is probably most closely related, by its coriaceous, narrowly elliptic to lanceolate leaves, with a rather obscure tertiary venation (vs. membranous, obovate to oblanceolate leaves, with conspicuous tertiary venation); with its flowers borne on much longer pedicels (usually> 20 mm long), often developing before the leaves (vs. shorter pedicels and with flowers concurrent with the leaves). Fig. 1. – Living plant of OCHna sambiranensis Callm. & Phillipson at Kalabenono corresponding to Callmander & al. 703. [Photo: M. W. Callmander] Etymology . – The species epithet refers to the Sambirano biogeographicregion towhich Ochna sambiranensis appears to be restricted.