Z. pentlandii has immaculate (or very rarely spotted) oblong-lanceolate leaves, slightly constricted above the short, hastate, rounded lobes; the apex is obtuse (or sometimes acute) with a subulate, seldom recurving tip. The spathe is clear lemon-chrome yellow, is funnel-shaped, greenish outside below and rounded at the apex with an abruptly subulate tip.
Perennial herb, up to 0.6 m high. Leaves oblong-hastate, blade up to 350 mm long and 150 mm wide, usually immaculate. Spathe lemon-chrome-yellow with a purple blotch at base.
Plants glabrous, up to 60 cm, seldom taller. Leaves deciduous, up to 60 cm long, usually shorter than the peduncles, petiolate, petioles up to 30 cm long, clasping at the base; blade yellowish grass-green, usually immaculate (seldom maculate) oblong-elliptic to oblong-lanceolate, hastate, obtuse to acute, abruptly apiculate, up to 35 cm long and 15 cm wide. Spathe up to 13 cm long, lemon-chrome yellow with a dark purple blotch at the base inside, slightly marked with green outside at the junction with the peduncle, also at the apiculate apex, regularly funnel-shaped; limb loosely folded, seldom recurved back-wards, with a 0.5-2 cm long apiculus. Spadix stipitate, usually less than half as long as the spathe: male zone slightly more than two thirds of the length, anthers yellow; female portion less than one third of the length. Ovaries 3-locular, 5-8 ovules in each locule. Fruit green, few in number, with up to 20 seeds.