Plante hémicryptophyte (plante vivace), à souche épaisse émettant des tiges dressées, creuses, simples ou ramifiées.. Les feuilles, légèrement glauques, plus ou moins sessiles, sont entières, ovales à oblongues (6-10 cm de long pour 2-3 cm de large), à plusieurs grandes nervures divergentes. L'inflorescence est une panicule corymbiforme, à ramifications rapprochées et portant des fleurs de couleur rose clair, parfois blanche. Les cinq pétales sont soudés dans la partie basale pour former un tube marqué d'une bosse plus courte que l'ovaire et située au-dessus du calice à bords enroulés. Le fruit est un akène glabre, surmonté d'un pappus (faisceau de soies).
Détermination
Assez simple.
Espèces proches
Le Centranthe à trois nervures peut être rapproché du Centranthe rouge (Centranthus ruber (L.) DC.) dont il se différencie cependant très nettement par une inflorescence plus légère, des feuilles plus étroites ainsi que la corolle des fleurs dont le tube est marqué par une simple bosse et non munie d'un éperon.
Période d'observation
Cette espèce fleurit d'avril à juin.
Biologie-éthologie
Plante se développant en contexte de couloirs rocheux granitiques d'ubac, dans des anfractuosités et des fissures de falaises, entre 150 et 200 m d'altitude.
Biogéographie et écologie
Espèce endémique cyrno-sarde. Pour la France métropolitaine, uniquement présente en Corse du Sud, à raison d'une seule station dans les environs de Bonifacio.
Sources Gamisans, J. & Jeanmonod, D. 2013. Flora Corsica. Seconde édition revue et augmentée. Société Botanique du Centre Ouest : 1074 p. Tison, J.-M., De Foucault, B. (coords). 2014. Flora Gallica - Flore complète de la France. Biotope Éditions, Mèze : xx + 1196 p.
The map presents a summary at the 10 x 10 km grid of the observation data for the species transmitted to the SINP. These data have been subjected to validation filters.
Distribution map from the Atlas of Departmental Biodiversity and Marine Sectors program
Current distribution in metropolitan France
The map presents a reference distribution layer of the species at the scale of departments and marine sectors. The presence and absence data were established by expertise within a network of partners. This reference distribution is used in the validation process of the SINP data at the INPN level.
Distribution map from the Atlas of Departmental Biodiversity and Marine Sectors program
Certain presence
Corresponds to a report on the basis of at least one observation proved within a period of 10 years (20 years for little-known invertebrates) preceding the year and no presumption of extinction since obtaining the last data nor doubt on reproductive and implemented nature of this population. For migratory species, the presence indicated concerns areas of reproduction.
Probable presence
This status is based on one or more of the following criteria:
search of species incomplete but presence of supportive environments;
ecology of the species consistent with the hypothesis of his presence;
the last reliable sighting is older than 10 years compared to the reference date, no recent specific research and no presumption of extinction from that date [vertebrates, invertebrates and plants well studied (rhopalocera, grasshoppers, dragonflies ...)] ;
the last reliable observation being older than 20 years, no recent specific research and no presumption of extinction from that date [poorly known taxa: fungus, many invertebrates...].
Probable or certain absence
This point covers the absence, more difficult by nature to demonstrate than presence. This status is based on one or more of the following criteria:
intensive but unsuccessful targeted research;
lack of adequate environments;
unobserved species while its presence is easily detected;
unlikely presence for historical or biogeographical reasons.
This status must be assigned to a department in which the presence of the species is casual.
Absence due to a proven extinction
Particular case of absence due to a proven extinction less than a half century ago (older disappearances are treated as "no probable or definite").
No information
In the state of knowledge, we can not comment on the presence or absence in the current department. This is the default status when not comprised in one of the previous categories or whenever there is doubt.