previous arrow
next arrow


Perennial herbs, slender or robust terrestrial, climbers, sometimes epiphytic, or floating aquatics, with watery, acrid, or milky juice. Stems rhizomatous or tuberous or cormous. Leaves simple or compound, basal, or cauline and alternate, petioled, base sheathing, blades variously lamellate with pinnate or palmate-netted venetion. Inflorescence of spadix, subtended by large, showy spathe. Flowers bisexual or unisexual, if unisexual, plants more often monoecious with males towards apex and females towards spadix-base, often with foetid-odour.  Perianth rare in unisexual flowers, of 4-6 segments in bisexual flowers. Stamens 4-8, anthers 2-4 celled. Carpels connate in 1-3 celled ovary, ovules 1-many, placentation various. Fruit a berry. Seeds 1-few.

Key to the Genus

Serial Key Reference
1a. Leaves ensiform, unifacial; raphides absent Acorus
1b. Leaves with bifacial blade; raphides present 2
2a. Plants free-floating aquatics Pistia
2b. Plants terrestrial or halophytes, never floating 3
3a. Flowers with obvious perigone of free or fused tepals 4
3b. Flowers without perigone of free or fused tepals 6
4a. Higher order leaf-venation parallel-pinnate; tissues with abundant trichosclereids Spathiphyllum
4b. Higher order leaf-venation clearly reticulated; tissues without trichosclereids, or trichosclereids very few 5
5a. Stem typically subterranean, tuberous or rhizomatous, if sometimes aerial and creeping or scrambling, then aculeate Lasia
5b. Stem aerial, not tuberous or rhizomatous, never aculeate Pothos
6a. Flowers bisexual; spadix uniform in appearance with flowers of only one type 7
6b. Flowers unisexual; spadix clearly divided into basal female zone and apical or intermediate male zone 9
7a. Ovary 2-5 locular. Seeds globose to oblong Monstera
7b. Ovary 1-locular or incompletely 2-locular 8
8a. Ovules amphitropous to anatropous, solitary Scindapsus
8b. Ovules anatropous, more than one Rhaphidophora
9a. Stamens of each male flower free, or only the filaments connate 10
9b. Stamens of each male flower entirely connate into a distinct synandrium 15
10a. Spadix never entirely enclosed by spathe in a basal ‘kettle’ formed of connate spathe margins 11
10b. Spadix entirely enclosed by spathe in a basal ‘kettle’ formed of connate spathe margins. Plants always halophytic or aquatic Cryptocoryne
11a. Higher order leaf-venetion parallel pinnate 12
11b. Higher order leaf-venetion reticulate 14
12a. Plant usually climbing or epiphytic; inflorescence secreting resin from spathe or spadix at anthesis Philodendron
12b. Plant always terrestrial, rarely aquatic, never climbing or epiphytic; inflorescence not secreting resin at anthesis 13
13a. Seed with copious endosperm, embryo relatively small; ovules several to many Homalomena
13b. Seed without endosperm, embryo large; ovule 1 Aglaonema
14a. Shape of leaf-blade dracontioid; leaf solitary Amorphophalus
14b. Shape of leaf-blade diverse, never dracontioid; leaves usually several Typhonium
15a. Laticifers simple 16
15b. Laticifers anastomosing 17
16a. Synandria connate; thecae of adjacent synandria encircling pits in the spadix, each pit with a somewhat prominent upper margin; leaf peltate Ariopsis
16b. Synandria free; leaf not peltate Dieffenbachia
17a. Plants climbing hemiepiphytes, (sometimes creeping when young); internodes long; berries connate into a syncarp Syngonium
17b. Plants terrestrial or geophytic, not climbing (rarely aquatic); internodes very short; berries free from each other 18
18a. Spadix with an appendix. Paleotropical plants 19
18b. Spadix without an appendix 20
19a. Placentas parietal; ovules many; leaf-blades always entire Colocasia
19b. Placentas basal; ovules few; leaf-blades entire or pinnatifid Alocasia
20a. Ovary completely to incompletely 2-several locular, placentas parietal, deeply intrusive; neotropical plants 21
20b. Ovary clearly 1-locular, placentas not intrusive; paleotropical plants 22
21a. Spathe-tube subglobose, inflated; synadrodes (sterile flowers) between male and female flowers more or less prismatic. Female zone of spadix free Xanthosoma
21b. Spathe-tube always convolute; synadrodes (sterile flowers) between male and female flowers distinctly prismatic Caladium
22a. Female flowers with staminodes; spathe not constricted; stem trunk-like or creeping Steudnera
22b. Female flowers without staminodes; spathe with 1 or 2 constrictions; stem tuberous, stoloniferous Remusatia