A new species of Amorphophallus (Araceae) from northeastern Thailand.

Amorphophallussakonnakhonensis Chatan & Promprom, a new species from northeastern Thailand, is described and illustrated. The new species is most similar to A.harmandii Engl. & Gehrm. and A.linearis Gagnep., but it is distinguished by the combination of characters as follows: clear differences with A.harmandii are shorter style; disc-like, slightly smooth surface, concave centre, ca. 0.2 × 0.1 mm stigma; slightly cylindrical, slightly narrower upper part of staminate flower zone; slightly cylindrical to elongate-fusiform, erect or slightly erect, creamy white appendix. The clearly distinct morphology with A.linearis are disc-like, slightly smooth surface, concave centre, ca. 0.2 × 0.1 mm stigma; elliptic or obovate leaflet; 1-3 cm long, creamy white appendix. The preliminary conservation status was assessed, and the distinct characteristics of similar species were discussed.