Protologue: Pflanzenr. 48 (IV.23C) (1911): 84
Synonym: Hydrosme aspera Engl.
Leaf solitary. Petiole c. 180 cm long, c. 4 cm in diam. background marbling shades of deep dark green and mid green, topped with white spots, scattered, oval to elongate-elliptec with tiny dots in the centre, with basal part somewhat sand-like. Lamina up to 100 in diam, rachises naked at the central point. Leaflets elliptic to elliptic-lanceolate, 6-18 cm long, 4-8 cm wide, apex long acuminate to caudate, mid-green adaxially. Inflorescence solitary with long peduncle, 50-150 cm long. Spathe ovoid to triangular ovoid, much shorter than spadix, not constricted. Lower spathe convolute, outside mid greenish background suffuse with small and numerous dark brownish spots near the margin, inside whitish, smooth or small muricate warts at base. Limb erect, acute, furrowed with numerous small dark brownish dots. Spadix sessile, longer than spathe, c. 60 cm long. Female zone somewhat cylindrical, c. 13 cm long. Pistils closely packed. Ovaries subglobose, greenish. Style c. 0.2 cm long, brownish, very obvious. Stigma c. 0.1 cm in diam., shallowly bi-lobed, orange. Sterile zone absent. Male zone somewhat cylindrical, c. 151 cm long, ivory. Thecae opening through elongated apical pores. Appendix tapering toward the apex, creamy. Infructescence bearing withering spathe, c. 165 cm long. Fruit berry, compact arranged.
Distribution: Endemic to Sumatera (Bengkulu and Lampung Provinces)
Habitat: Found along side of road to Bengkulu, in slightly open area, sometimes in disturbed forest.
The description presented here is from a plant observed by Yuzammi. However the identification as Amorphophallus asper remains in doubt. More specimens of similar morphology have been found in southern Sumatera with slightly different dimensions and colours. However, for all specimens found it remains to be seen whether they represent a separate species, for which the name Amorphophallus asper might well apply, or that they are small specimens of Amorphophallus gigas, with which they share many characters but mainly differ in their smaller stature. This will be further studied by W.L.A. Hetterscheid for an upcoming full scale revision of the East Asian Amorphophallus species.
Amorphophallus asper as presented here, seems to gradually decrease in numbers through ongoing road construction. Mostly the populations are found on the edge of forests adjacent to the Sumateran Highway. The inflorescence size may vary in size from 40 cm up to 2 m.