Amorphophallus prainii

The following info has been extracted from Aroideana, Volume 19, a publication of the International Aroid Society.  You'll note that this is just a small portion of the extensive descriptive information available in the Aroideana 19:

Tuber depressed globse, 4-25 cm in diameter, 2.5-15 cm high
Leaf petiole smooth, rarely slightly rugulose at the base, 10-210 cm long, 0.5-10 cm in diameter at base, soft or rather turgid, background color variable, whitish green or reddish brown, mottled with numerous small, blackish green spots and large circular or oval, creamy white spots, often confluent and internally with small blackish green spots or with a reddish brown center, sometimes nearly entirely covering the surface, the base often with a bluish purple hue
Leaf lamina highly dissected, 250 cm in diameter, 1.5-10 cm in diameter
Spathe 10-25 (-40) cm long, 10-25 (-40) cm in diameter, base strongly convolute, shallowly constricted at the top, limb obliquely erect during female anthesis, stronly reflexing just prior to male anthesis, base outside yellowish green with whitish spots and streaks or with a purplish hue and whitish spots or very pale pinkish white with small, dark green, punctiform spots and large rounded, whitish spots, margin pinkish, inside dark maroon, limb outisde yellowish green or bright pale green with shitish spots, the margin without spots and flushed with purple, inside pale yellowish white with bright green stripes along the margin or the latter entirely bright green with small, shortly ridge-like warts
Spadix shorter than spathe in small specimens, otherwise longer, 9-35(-55) cm long, shortly stipulate, stipe ca. 1 cm long
Dormancy May be stored dry as per volume 19, but I've lost 3 to fungus despite careful storing and so wil assure a fungicide soak and dusting before storing the next time it goes dormant

(extracted with permission from Aroideana volume 19)