Taxonomie
Synonymes
Sarcochilus radicosus Kraenzl.Statut liste rouge -
Vulnérable (VU) , évaluée le 26/10/2015Espèce protégée -
en Province Sud , en Province Nord
Description
Description Générale
Plante qui peut ressembler à un Vanda miniature.
Racines longues, blanchâtres qui partent de la moitié inférieure de la tige et s'accrochent sur le support, ce qui éloigne la tige de ce support.
Habitat
On la rencontre le plus souvent à la base d'arbrisseaux ou sur les rochers, en maquis minier (M).
Feuille
Tige fine, 1 à 2 mm, pouvant atteindre exceptionnellement 15 cm de haut, portant dans sa partie supérieure des feuilles charnues, fines, vert ou sombre, piquetées de points rouges.
Phénologie (Fleur)
Hampe florale longue, aud-dessus de la plante portant de nombreuses petites fleurs blanches avec des marques jaunes sur le labelle. Les fleurs s'ouvrent plus ou moins selon les plants.
La plante émet souvent plusieurs hampes. Il existe une variation dans la couleur des fleurs allant du blanc pur au rose. (peu fréquent)
Fruits
Fruit fin et très allongé.
Sarcochilus rarus is an endemic epiphyte and saxicolous orchid of New Caledonia. Its distribution is disjointed with somesub-populations on the northweastern part of Grande Terre from Tia to Tiébaghi, in Belep and some others on the extreme south part of Grande Terre (even île Ouen). S. rarus occurs in shrubland at an altitudinal range 35-550 m. asl. With 11 localities threatened by plant bugs, bushfires and nickel mining, a decline of population and habitat quality is estimated. Total population size is estimated to be fewer than 10,000 mature individuals with sub-population fewer than 1,000 individuals. using criteria C, S. rarus qualifies as Vulnerable C2a(i).
Aire géographique
Sarcochilus rarus is an endemic epiphyte and saxicolous orchid of New Caledonia. Its distribution is disjointed with somesub-populations on the northweastern part of Grande Terre from Tia to Tiébaghi, in Belep and some others on the extreme south part of Grande Terre(even île Ouen).
Population
S. rarus is not a common orchid, and from experts population is decreasing. Field observation report around ten mature individuals by station. Total population size is estimated to be fewer than 10,000 mature individuals with sub-populations fewer than 1,000 individuals.
Habitat
S. rarus occurs in shrubland at an altitudinal range 35-550 m asl.
Menaces
Cochineal and rust attacks have been observed on S. rarus. As S. rarus is growing on low branches, it is also threatened by bushfires. Finally on Goro, Koniambo Kaala and Tiébaghi, nickel mining constitutes a supplementary threat to S. rarus.
Conservation
S. rarus is protected by legislation in Province Nord and in Province Sud and occurs in one protected area : réserve naturelle du Cap N’Dua. Field surveys have to be rekindled on lowland ultramafic mountains of the west coast. Due to the estimated population decrease, it would be necessary to monitor population trend in protected areas as well as on mines. As Port Boisé locality constitutes the biggest sub-population, it would be a priority to fence it.
Bibliographie
Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.
Hallé N.; Aubréville A.; Leroy J. F.; 1977. Flore de la Nouvelle-Calédonie et dépendances. Volume 8: Orchidaceae.
Morat, P.; Jaffré, T.; Tronchet, F.; Munzinger, J.; Pillon, Y.; Veillon, J.-M. and Chalopin, M. 2012. Le référentiel taxonomique Florical et les caractéristiques de la flore vasculaire indigène de la Nouvelle-Calédonie [The taxonomic database « FLORICAL » and characteristics of the indigenous flora of New Caledonia]. Adansonia sér 3(34) , p.177-219.
Experts
Assessor(s): Butin, J., Laudereau, C., Amice, R., Fleurot, D., Frayssinet, I., Garnier, D., Letocart, D., Letocart, I.
Reviewer(s): Tanguy, V.
Contributor(s): Faria, E.
Facilitator(s): Chanfreau, S.