La révision taxonomique et nomenclaturale présentée dans cet article concerne le genre Marsilea L. à Madagascar. Elle complète et amende la dernière révision de Launert (1984) et la dernière synthèse de Roux (2009). Ce nouveau traitement inclut :

1) Une clé d'identification originale;

2) La description et l'illustration de deux espèces nouvelles : Marsilea globulosa I.Bouchart, sp. nov. dont le sporocarpe est globuleux, de petite taille avec une dent supérieure fortement aiguë et acuminée, et Marsilea pyriformis I.Bouchart, sp. nov. dont le sporocarpe est pyriforme avec une dent supérieure très longue, aiguë et souvent fortement courbée à mi-longueur ;

3) Des lectotypifications pour Marsilea muscoides Lepr. ex. A.Braun, Marsilea trichopoda Lepr. ex. A.Braun, Marsilea diffusa Lepr. ex. A.Braun f. madagascarensis et Marsilea diffusa Lepr. ex A.Braun var. cornuta A.Braun ex Kuhn ;

4) Le signalement pour la première fois à Madagascar d'une espèce africaine : Marsilea macrocarpa C.Presl ;

5) la description et l'illustration des cinq autres espèces de Marsilea malgaches.

Ces modifications taxonomiques et nomenclaturales portent à sept le nombre d'espèces de Marsilea présentes à Madagascar dont deux sont endémiques.

A new endemic species of Sagina L., Sagina hookeri Timaná, sp. nov. (Caryophyllaceae) is described for the flora of Île Amsterdam, in the southern Indian Ocean (French Southern and Antarctic Lands). Differences between this taxon and S. diffusa (Hook.f.) Timaná (endemic to the neighboring island of Saint-Paul) and S. procumbens L. (introduced in several circum-austral islands) are discussed, and an identification key to those three Sagina species occurring in Saint-Paul and Amsterdam islands is presented.

A morphological study of the monospecific genus Rhipidantha Bremek. from Tanzania leads to its inclusion in Pauridiantha Hook.f.; a new combination, Pauridiantha chlorantha (K.Schum.) Ntore & O.Lachenaud, sp. nov., is therefore published, and a full description of this hitherto little-known species is provided. Two new Pauridiantha species from Atlantic Central Africa are also described and illustrated: Pauridiantha gracilipes O.Lachenaud & Ntore, sp. nov. and Pauridiantha principensis Ntore & O.Lachenaud, sp. nov. The former species is endemic to the Ogooué delta in Gabon, and resembles P. liebrechtsiana (De Wild. & T.Durand) Ntore & Dessein, but differs by the 2-locular ovary, the very long fruiting pedicels (12-18 mm) and the frequent presence of spines on the older stems – the last two characters being unique in the genus. The second species is endemic to Príncipe island, and differs from P. insularis (Hiern) Bremek., from the neighbouring island of São Tomé, by the more ascending secondary leaf veins lacking domatia in their axils, longer pedicels, and glabrous stipules. The conservation status of all three species is evaluated acccording to IUCN criteria: P. chlorantha (K.Schum.) Ntore & O.Lachenaud, comb. nov. is assessed as Endangered, P. gracilipes O.Lachenaud & Ntore, sp. nov. as Critically Endangered, and P. principensis Ntore & O.Lachenaud, sp. nov. as Near-threatened. Finally, Pauridiantha microphylla R.D.Good is placed into synonymy of P. canthiiflora Hook.f.

Vepris mbamensis Onana, sp. nov., qui présente des pétiolules renflés, est reconnue distincte des autres espèces connues de Vepris Comm. ex A.Juss. en Afrique après étude du matériel africain du genre. La nouvelle espèce est décrite et typifiée. La clé des espèces camerounaises du genre Vepris est mise à jour afin d'y intégrer la nouvelle espèce. Le spécimen sur lequel est basé le nom invalidé Diphasia mildbraedii Engl. de la République Centrafricaine (R.C.A.) montre des caractères morphologiques identiques à ceux de V. adamaouae Onana, notamment l'inhabituelle ramiflorie dans le genre. Par conséquent le premier nom est placé en synonymie du second et l'aire de répartition est étendue en R.C.A. L'identification des matériels récoltés au Nigeria étend aussi la répartition de V. adamaouae à l'ouest. Une clé permettant de distinguer les espèces camerounaises à fruits sillonnés est présentée. Vepris mbamensis Onana, sp. nov. et V. adamaouae sont illustrées, et une carte de distribution des deux espèces est présentée.

A new species of Syzygium Gaertn. (Myrtaceae) is described from North East India: Syzygium nivae Barbhuiya, J.Sarma & S.Dey, sp. nov. The new species is a rheophyte, which is restricted to the Kopili riverbed of West Karbi Anglong district of Assam. The present species shows little affinity with Syzygium khasianum (Duthie) N.P.Balakr. in having lanceolate leaves, paniculate inflorescence and calyptrate petals, but differs in various aspects, such as shrubby rheophytic plant habit, narrower leaves, non-caudate leaf apex, shorter peduncles, larger flowers etc.

Three new species of Begonia section Erminea A.DC. from north-east Madagascar are described and illustrated. They share a tuberous habit, four tepaled male flowers and six tepaled female flowers, which are typical of that section. Begonia ambanizanensis Scherber. & Duruiss., sp. nov. differs from the other species in that section by the symmetric, sub-orbicular, succulent leaf blades. Begonia ambodiforahensis Scherber. & Duruiss., sp. nov. is compared to B. antongilensis Humbert and B. erminea L'Hér. but it differs from both by the combination of an acaulescent habit and the numerous lanceolate leaves with red margins and spiculiform red hairs on the blade. Begonia harimalalae Scherber. & Duruiss., sp. nov. is also compared to B. erminea from which it differs by the thicker, larger leaves, which are glabrous, with the margins shallowly and sparsely serrate vs densely biserrate.

A new tree species, Didelotia gracillima Jongkind, sp. nov., from Liberia and Ivory Coast is described. It differs from D. brevipaniculata J. Léonard, with which it was earlier confused, by its narrower and pendulous inflorescence and its red flowers and much longer stamens.

French botanist A.R. Franchet (1834-1900) has described near 60 taxa in the genus Primula L., 16 taxa from them were discussed in a first publication. Our current paper will continue the researches devoted to the typification of Primula names, on the base of expert studying the specimens in herbaria BM, E, G, K, LE, MHA, MW, NS, NSK, P, W, WU, Z and open databases. In 1886 Franchet published an article: “Observations sur deux Primula monocarpiques de la Chine et descriptions d'espèces nouvelles de la Chine et du Thibet oriental” and described 11 new species: P. davidii Franch., P. forbesii Franch., P. heucherifolia Franch., P. incisa Franch., P. malacoides, Franch. P. malvacea Franch., P. membranifolia Franch., P. moupinensis Franch., P. oreodoxa Franch., P. ovalifolia Franch. and P. poissonii Franch. For P. davidii and P. heucherifolia we found only one herbarium sheet for each and they will be holotypes. For eight species: P. forbesii, P. malacoides, P. malvacea, P. membranifolia, P. moupinensis, P. oreodoxa, P. ovalifolia and P. poissonii were selected lectotypes from several herbarium sheets. The name Primula incisa is later homonym and early was used by Lamarck (1779), so correct name for this taxon is P. blinii H. Lév.

A new species of Astrotrichilia (Harms) J.-F. Leroy ex T. D. Penn. & Styles (Meliaceae, Melioideae) from seasonally dry forests in northern Madagascar is described. The new species is most similar to A. asterotricha (Radlk.) Cheek, but differs in a number of vegetative characters and has a distinct geographical distribution. A previous study of the new species has shown it to possess secondary compounds with antiproliferative properties towards ovarian cancer cells, highlighting the urgent need for its conservation. Images, a distribution map, and a preliminary assessment of risk extinction using the IUCN Red List Criteria are provided for the new species.

Arabis nuda Bél., known for more than 160 years as Drabopsis verna K.Koch and more recently as Draba nuda (Bél.) Al-Shehbaz & M.Koch, was based on an illustration unaccompanied by a text and until now has been assumed to be the type, though the name has never been typified. The discovery of a specimen in the herbarium of Muséum national d'Histoire naturelle (P05413412), on which that original illustration was based, led to designating that specimen herein as the lectotype.

João da Silva Feijó (1760-1824), naturaliste portugais engagé dans les célèbres « Voyages Philosophiques» sous l'égide de la couronne portugaise, entreprit la première expédition scientifique exclusivement consacrée à l'étude de l'histoire naturelle dans les îles du Cap Vert, entre 1783 et 1796. Pour le compte du Musée royal d'Ajuda à Lisbonne, Feijó effectua les premières grandes récoltes botaniques dans tout l'archipel (1783-1789) qui, avec ses manuscrits, offrent un aperçu de la flore du Cap Vert telle qu'elle existait à la fin du XVIIIe siècle. Cette étude révèle des données uniques sur l'héritage des collections de Feijó, avec des détails de son expédition à travers l'archipel du Cap Vert. Ses récoltes, longtemps restées sous l'anonymat et éparpillées dans de nombreux Herbiers, ont été réunies spécialement pour cette étude. En outre, les manuscrits relatifs à ses récoltes d'herbiers sont discutés et les correspondances entre les déterminations du naturaliste et les noms scientifiques actuels ont été établies. Une numérotation de son herbier est proposée ici, fondée sur le système sexuel linnéen afin de faciliter les futures études de cette collection historique. Chaque spécimen d'herbier a été étiqueté avec de précieux renseignements issus des archives (récolteur, date) qui ont pour intentions de rendre hommage au naturaliste et de sortir cette collection du silence dans lequel elle se trouvait depuis plus de deux siècles. Enfin, les diverses tribulations de l'herbier Feijó au fil des années sont décrites et expliquées.

During investigation of the genus Bufonia L., in various herbaria of Iran, a new species, B. iranica Z.Rostami, Assadi & F.Ghahrem., sp. nov., was recognized and thus is described here. This new species is closely related to B. enervis, with some morphological differences such as size and shape of the perianth, and the seed shape. A key for the species occurring in Iran, illustrations and a distribution map of the new and related species are provided. The seed morphology was studied using a scanning electron microscope.

The names Arctotis staticifolia Poir. and Arctotis tenuifolia Poir. were validly published by Jean Louis Marie Poiret based on material collected from “Cap de Bonne-Espérance” and stated to be lodged in the Herbier Desfontaines. No original material for Arctotis staticifolia has been traced. The protologue is inconsistent with any known Arctotis L. species and previous treatment of A. staticifolia as a synonym of Gazania linearis (Thunb.) Druce var. linearis is not supported. The protologue for Arctotis staticifolia is most consistent with a narrow-leaved taxon of Dimorphotheca Vaill. ex Moench and specifically D. nudicaulis (L.) DC. var. graminifolia (L.) Harv. A neotype for Arctotis staticifolia is designated consistent with our interpretation and the name is formally placed in the synonymy of Dimorphotheca nudicaulis var. graminifolia. Arctotis tenuifolia Poir. has previously been treated as a synonym of Dimorphotheca nudicaulis var. graminifolia. Original material was located and the name Arctotis tenuifolia Poir. is here lectotypified and is placed in the synonymy of Ursinia tenuifolia (L.) Poir. subsp. tenuifolia. Arctotis tenuifolia Poir. is a later heterotypic homonym of Arctotis tenuifolia L. and is therefore nomenclaturally illegitimate. A lectotype is designated for Sphenogyne tenuifolia (L.) DC. var. heterochroma Harv., a synonym of Ursinia tenuifolia subsp. tenuifolia.

A large colony of duckweeds (Araceae: Lemnoideae) grows on the constantly wet, vertical wall of the rock shelter behind the Llanos de Cortés waterfall of the Potrero River, Guanacaste province, Costa Rica, the first such case ever documented. Its unique hygropetric environment is described. The colony covers several square meters distributed in several different patches, and consists almost entirely of Wolffiella oblonga (Phil.) Hegelm., with much fewer individuals of Lemna valdiviana Phil. and L. aequinoctialis Welw. This also constitutes the first case of the genus Wolffiella Hegelm. growing in a hygropetric manner (an extremely rare condition for duckweeds) and the first record of W. oblonga in Costa Rica.