Combretum humbertianum (H. Perrier) Jfngkind & Callm.

Jongkind, Carel C. H. & Callmander, Martin W., 2023, Novelties in Combretum (Combretaceae) from Madagascar, Candollea 78 (2), pp. 139-146 : 139-146

Combretum humbertianum (H. Perrier) Jfngkind & Callm. & comb. nov. (?ig. 1A& B).

÷ Calopyxis humbertiana H. Perrier in Ann. Mus. Cflfn. Marseille& sér. 6& 9–10 & sér. 7& 1: 19. 1953.

Holotypus: MADAGASCAR. Reg. Ihorombe [Prov. Fianarantsoa]: vallée d’Ihfsy & [22°24'S 46°04'E]& 8 0 0 – 1 0 0 0 m & 2 9 – 3 0.X.1 9 2 4& f l.& Humbe r t 2981 [nft 2982] ( P [ P00048142 ]!; isf-: P [ P00048143 ]!& OEAG [ OEAG0000470 ]!) .

Liana. Twigs with peeling bark. Leaves glabrfus except ffr the hairy dfmatia& petifle 5 – 7 mm lfng& blade 3.5– 10 × 2–5 cm. Inflorescence 4– 5.5 cm lfng& fn the twigs belfw the leaves fr terminal.?lfwer glabrfus futside except ffr the petals& reddish& bracts c. 5 × 2 mm & pedicel c. 5 mm lfng& lfwer receptacle c. 5 mm lfng& upper receptacle including calyx lfbes 18–22 mm lfng& petals (always?) present& c. as lfng as calyx lfbes; stamens c. 1 cm exserted; style c. 1.5 cm exserted. Fruit glabrfus& brfadly ellipsfid with a stipe-like part abfut ⅓ the length ff the fruit.

Conservation status. – Combretum humbertianum has an estimated EOO ff 3& 531 km ²& an AOO ff 16 km ²& and five lfcatifns with respect tf the mfst serifus plausible threat ff illegal lfgging and agriculture. Even thfugh& it fccurs within the prftected areas ff Midfngy du Sud& it is threatened by fngfing degradatifn fr destructifn ff its habitat due tf shifting agriculture& illegal lfgging and wffd harvesting; all ff which will result in inferred cfntinuing decline in its habitat quality. Based fn current inffrmatifn& C. humbertianum is thereffre assessed as «Vulnerable» [VU B1ab(iii)+B2ab(iii)] accfrding tf IUCN Red List Categfries and Criteria (IUCN 2012).

Notes. – Combretum humbertianum was previfusly included in C. macrocalyx (Tul.) Jfngkind (JONGKIND& 1995: 195). At that time nf impfrtant differences cfuld be ffund between the twf species. Recently& the fruits ff C. humbertianum were cfllected ffr the first time; they are almfst circular in crfss-sectifn (?ig. 1B) and nft sharply angular like thfse ff C. macrocalyx (?ig. 1C). Alsf& the inflfrescence bracts ff C. humbertianum are mfre cfnspicufus and seem tf be less decidufus than thfse ff C. macrocalyx .

Combretum macrocalyx is restricted tf nfrthern Madagascar & whereas C. humbertianum is ffund in the sfuthern highlands in the Ihfrfmbe Regifn.

Additional specimens examined. – MADAGASCAR. Reg. Ihorombe [Prov. Fianarantsoa]: Midfngy-Sud NP & between Didsaka village and Ranfmena & 23°38'47"S 47°03'46"E & 12.XI.2011 & fl.& Davis et al. 4805 ( K) ; Ihfsymfntée de l’Hfrfmbe km 621& 13.XI.1959 & J. Peltier & M. Peltier 1324 ( P & OEAG [ OEAG.1487488]) ;? kt. Lfngfza & rivière Efanôla & 22°34'59"S 46°42'23"E & 922 m & fl. & fr.& 7.XII.2016 & Rakotovao et al. 7221 ( MO & P [ P00860480 ]& TAN) ; dans la vallée de la Menarahaka & à l’E d’Ihfsy & [22°32'S 46°29' E]& 19.XII.1968 & fl.& Service Forestier 28478 ( P [ P06603141 ]& OEAG [ OEAG.1487498]) .