Species of the water fern Salvinia are well known for their extremely water-repellent floating leaves. The architecture of Salvinia surfaces is of great interest for biomimetic applications, because submersed in water, they retain air films for a long period. Knowledge of these surfaces is also important for pest control, since one species (Salvinia molesta D.S. Mitch.) is a pantropic invasive aquatic weed. The micromorphology of the leaf surfaces of six representative species has been characterized by scanning electron microscopy. Based on their morphology, the trichomes are classified in four types, named after the typical species. Among the species examined, numbers, distribution, and sizes of the trichome types vary significantly. The simplest types, the Cucullata trichomes, are multicellular, uniseriate, and up to 800 [micro]m high. Groups of two multicellular, uniseriate trichomes are described as the Oblongifolia trichomes. The Natans trichomes are grouped as four multicellular, uniseriate trichomes. The Molesta trichomes are composed of four trichomes, which are connected by the second last apical cells of the trichome. The ontogeny of the Molesta trichome groups was puzzling and resulted in various names being applied to them ("Kranchenhaare," "egg-beater," or "coroniform" hairs). Their unique development from four solitary uniseriate trichomes to groups of four connected trichomes is described in detail. Key words: Salvinia, hierarchical structures, trichomes, water ferns. On connait bien l'impermeabilite extreme des feuilles flottantes des especes de fougeres aquatiques du genre Salvinia. L'architecture des surfaces des Salvinia spp presente un grand interet pour des applications en biomimetisme, parte que lorsqu'elles sont immergees darts feau, elles retiennent des films d'air pendant de longues periodes. La connaissance de ces surfaces revet egalement de l'imponance pour la lutte biologique, puisqu'une espece (Salvinia molesta D.S. Mitch.) constitue une adventice aquatique envahissante pantropique. Les auteurs ont caracterise la micromorphologie de six especes representatives a l'aide de la microscopy electronique par balayage. Sur la base de leur morphologie, on classifie les trichomes selon quatre types, nommes d' apres des especes typiques. Parmi les especes exammnnes, les nombres, la distribution et les dimensions des trichomes types varient significativement. Les types les plus simples, les trichomes Cucullata, sont multicellulaires, uniseries et jusqu'a 800 [micro]m de haut. On decrit deux groupes de trichomes multicellulaires uniseries sous le type trichome Oblongifolia. On regroupe comme trichomes Natans quatre trichomes multicellulaires uniseries. Les trichomes Molesta component quatre trichomes relies par les cellules apicales penultiemes du trichome. L'ontogenie des groupes a trichomes Molesta presente un probleme conduisant a (utilisation de diverses appellations (pods " Kronchnhaare, " batteur d'oeuf, ou coroniformes). On decrit en detail leur developpement unique a partir de quatre trichomes solitaires uniseries conduisant a quatre groupes de trichomes inter relies. Mots-cles : Salvinia, structures hierarchiques, trichomes, fougeres aquatiques. [Traduit par la Redaction]