Key to A. pluricarinatum and morphologically similar species

1. Cataphylls persisting as a reticulum of fibers, hairlike; peduncle less than 2× longer than spadix; spadix longer than peduncle...... ........................................................................................................................................................................................ A. plowmanii

- Cataphylls with other fibers, not hairlike; peduncle more than 2× longer than spadix; spadix shorter than peduncle......................2

2. Petiole semilunar or obtrapezoidal, sulcate adaxially with acute margins, abaxially ribbed or obtuse; leaf blade with sharply wavy margins; inflorescence erect; spadix cylindric, clavate to rarely tapered...........................................................................................3

- Petiole subcircular, sulcate to canaliculate adaxially with obtuse margins, abaxially obtuse; leaf blade non–wavy or with slightly wavy margins; inflorescence pendent; spadix tapered .......................................................................................................................5

3. Petiole semilunar, sulcate adaxially with acute margins, abaxially surface 3–6-ribbed; spadix cylindric, greenish-vinaceous to purple at anthesis ..................................................................................................................................................... A. pluricarinatum

- Petiole obtrapezoidal ..........................................................................................................................................................................4

4. Leaf blade lanceolate to oblong; concolor; inflorescence shorter than half of the adult leaves; spadix tapered, green, gray-brown to purple at anthesis ....................................................................................................................................................... A. paraguayense

- Leaf blade elliptic to obovate; discolor; inflorescence longer than half of the adult leaves; spadix cylindric to clavate, yellowish-greenish to yellowish at anthesis ............................................................................................................................................ A. affine

5. Leaf blade up to 20 cm wide, narrowly lanceolate; spathe yellowish to greenishon both surfaces, striated at margins; spadix <10 cm long, lilac, with stipe 0.3–2.5 cm long.................................................................................................................... A. santaritense

- Leaf blade wider than 21 cm, elliptic or obovate; spathe lilac adaxially, greenish abaxially to vinaceous or brownish on both surfaces, absent striations at margins; spadix ≥ 9.5 cm long, vinaceous or brownish, sessile or stipe with 0.4 cm long..................6

6. Peduncle greenish, smooth (never ribbed); spathe lilac on adaxial surface, greenish on abaxial surface; spadix sessile or stipitate ca. 0.4 cm long; pollen yellowish; berries vinaceous at the base, purple at apex; seeds cream............................................. A. leonii

- Peduncle vinaceous to brownish, smooth or 1-ribbed; spathe vinaceous to brownish on both surfaces; spadix sessile; pollen whitish; berries entirely vinaceous; seeds yellowish..................................................................................................................... A. solitarium