Amorphophallus

Amorphophallus
Titan arum (Amorphophallus titanum) is the Amorphophallus with the largest inflorescence
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
Order:	Alismatales
Family:	Araceae
Subfamily:	Aroideae
Tribe:	Thomsonieae
Genus:	Amorphophallus Blume ex Decne.
Species
See text.

Amorphophallus (from Ancient Greek amorphos, "without form, misshapen" + phallos, "penis", referring to the shape of the prominent spadix) is a large genus of some 170 tropical and subtropical tuberous herbaceous plants from the Arum family (Araceae). A few species are edible as "famine foods" after careful preparation to remove irritating chemicals^[1].

Distribution

These are typical lowland plants, growing in the tropical and subtropical zones of the paleotropics, from West Africa to the Pacific Islands. None of them are found in the Americas although a remarkably similar but not closely related genus, Dracontium, has evolved there. Most species are endemic. They grow preferentially on disturbed grounds, such as secondary forests.

Description

These small to massive plants grow from a subterranean tuber, Amorphophallus tubers vary greatly from species to species, from the quite uniformally globose tuber of A. konjac to the elongated tubers of A. longituberosus and A. macrorhizus to the bizarre clustered rootstock of A. coaetaneus. From the top of this tuber a single leaf, which can be several metres across in larger species, is produced atop a trunk like petiole followed, on maturity, by a single inflorescence. This leaf consists of a vertical leaf stalk and a horizontal blade, which may consist of a number of small leaflets. The leaf lasts one growing season. The peduncle (the primary flower stalk) can be long or short.

As is typical of the Arum family, these species develop an inflorescence consisting of an elongate or ovate spathe (a sheathing bract) which usually envelops the spadix (a flower spike with a fleshy axis). The spathe can have different colors, but mostly brownish-purple of whitish-green. On the inside, they contain ridges or warts, functioning as insect traps.

The plants are monoecious. The spadix has tiny flowers: female flowers, no more than a pistil, at the bottom, then male flowers, actually a group of stamens, and then a blank sterile area. This last part, called 'the appendix', consists of sterile flowers, called staminodes, and can be especially large. There is no corolla.

Once the spathe opens, pollination must happen the same day. The inflorescence, in many species, emits a scent of decaying flesh, in order to attract insects, though a number of species give off a pleasant odor. Through a number of ingenious insect traps, pollinating insects are kept inside the spathe to deposit pollen on the female flowers, these stay receptive for only one day, while the male flowers are still closed. These open the next day, but by then female flowers are no longer receptive and so self pollination is avoided. The male flowers shower the trapped insects with pollen. Once the insects escape, they can then pollinate another flower. Amorphophallus species are used as food plants by the larvae of some Lepidoptera (butterfly and moth) species including Palpifer sexnotatus and Palpifer sordida.

The pollinated flowers then develop a globose berry as a fruit. These can be red, orange-red, white, white-and-yellow, blue.

The species Amorphophallus titanum, corpse flower or titan arum, is the world's largest unbranched inflorescence. It can reach a height of 2.5 m and a width of 1.5 m. A runner-up is Amorphophallus gigas, which is taller, but has a somewhat smaller flower. Amorphophallus konjac tubers are used to make konnyaku (コンニャク^?), a Japanese thickening agent and edible jelly containing glucomannan.

Some species are called voodoo lily, as are some species of Typhonium (also in the Araceae).

Species

Titan Arum - close-up

• Amorphophallus aberrans
• Amorphophallus abyssinicus
  • Amorphophallus abyssinicus subsp. abyssinicus
  • Amorphophallus abyssinicus subsp. akeassii
  • Amorphophallus abyssinicus subsp. unyikae
• Amorphophallus albispathus
• Amorphophallus albus
• Amorphophallus amygdaloides
• Amorphophallus angolensis
  • Amorphophallus angolensis subsp. angolensis
  • Amorphophallus angolensis subsp. maculatus
• Amorphophallus angulatus
• Amorphophallus angustispathus
• Amorphophallus ankarana
• Amorphophallus annulifer
• Amorphophallus antsingyensis
• Amorphophallus aphyllus
• Amorphophallus asper
• Amorphophallus asterostigmatus
• Amorphophallus atrorubens
• Amorphophallus atroviridis
• Amorphophallus barthlottii
• Amorphophallus baumannii
• Amorphophallus beccarii

Amorphophallus bulbifer

• Amorphophallus becquaertii
• Amorphophallus bonaccordensis
• Amorphophallus borneensis
• Amorphophallus boyceanus
• Amorphophallus brachyphyllus
• Amorphophallus brevispathus
• Amorphophallus bufo
• Amorphophallus bulbifera
• Amorphophallus calabaricus
  • Amorphophallus calabaricus subsp. calabaricus
  • Amorphophallus calabaricus subsp. mayoi
• Amorphophallus canaliculatus
• Amorphophallus carneus
• Amorphophallus chlorospathus
• Amorphophallus cicatricifer
• Amorphophallus cirrifer
• Amorphophallus coaetaneus
• Amorphophallus commutatus
• Amorphophallus consimilis
• Amorphophallus corrugatus
• Amorphophallus costatus

Amorphophallus prainii

• Amorphophallus coudercii
• Amorphophallus cruddasianus
• Amorphophallus curvistylis
• Amorphophallus dactylifer
• Amorphophallus declinatus
• Amorphophallus decus-silvae : West-Java Giant Amorphophallus
• Amorphophallus discophorus
• Amorphophallus dracontioides
• Amorphophallus dunnii
• Amorphophallus dzuii
• Amorphophilus eburneus
• Amorphophilus echinatus
• Amorphophallus eichleri
• Amorphophallus elatus
• Amorphophallus elegans
• Amorphophallus elliottii
• Amorphophallus excentricus
• Amorphophallus forbesii
• Amorphophallus galbra
• Amorphophallus gallaensis
• Amorphophallus gigas : Sumatra Giant Amorphophallus
• Amorphophallus gliruroides
• Amorphophallus glossophyllus
• Amorphophallus goetzei
• Amorphophallus gomboczianus
• Amorphophallus gracilior
• Amorphophallus gracilis
• Amorphophallus haematospadix
• Amorphophallus harmandii
• Amorphophallus hayi
• Amorphophallus henryi : Taiwan Amorphophallus
• Amorphophallus hetterscheidii
• Amorphophallus hewittii
• Amorphophallus hildebrandtii
• Amorphophallus hirsutus
• Amorphophallus hirtus
• Amorphophallus hohenackeri
• Amorphophallus hottae
• Amorphophallus impressus
• Amorphophallus incurvatus
• Amorphophallus infundibuliformis
• Amorphophallus interruptus
• Amorphophallus johnsonii
• Amorphophallus kachinensis
• Amorphophallus kiusianus
• Amorphophallus konjac : Devil's Tongue, Elephant Foot, Elephant-yam, Leopard Palm, Snake Palm, Umbrella Arum
• Amorphophallus konkanensis
• Amorphophallus koratensis
• Amorphophallus krausei
• Amorphophallus lambii
• Amorphophallus lanuginosus
• Amorphophallus laoticus
• Amorphophallus lewallei
• Amorphophallus linearis
• Amorphophallus linguiformis
• Amorphophallus longicornus
• Amorphophallus longiconnectivus
• Amorphophallus longispathaceus
• Amorphophallus longistylus
• Amorphophallus longituberosus
• Amorphophallus luzoniensis
• Amorphophallus lyratus
• Amorphophallus macrorhizus
• Amorphophallus manta
• Amorphophallus margaritifer
• Amorphophallus margretae
• Amorphophallus maximus
  • Amorphophallus maximus subsp. fischeri
  • Amorphophallus maximus subsp. maximus
• Amorphophallus maxwellii
• Amorphophallus mekongensis
• Amorphophallus merrillii
• Amorphophallus mildbraedii
• Amorphophallus minor
• Amorphophallus mossambicensis
• Amorphophallus muelleri
• Amorphophallus mullendersii
• Amorphophallus mysorensis
• Amorphophallus nanus
• Amorphophallus napalensis
• Amorphophallus napiger
• Amorphophallus nicolsonianus
• Amorphophallus obovoideus
• Amorphophallus obscurus
• Amorphophallus ochroleucus
• Amorphophallus opertus
• Amorphophallus paeoniifolius : Whitespot Giant Arum, Elephant Yam
• Amorphophallus palawanensis
• Amorphophallus parvulus
• Amorphophallus paucisectus
• Amorphophallus pendulus : Brunei Amorphophalus
• Amorphophallus perakensis
• Amorphophallus pilosus
• Amorphophallus plicatus
• Amorphophallus polyanthus
• Amorphophallus prainii
• Amorphophallus preussii
• Amorphophallus purpurascens
• Amorphophallus pusillus
• Amorphophallus putii
• Amorphophallus pygmaeus
• Amorphophallus rhizomatosus
• Amorphophallus richardsiae
• Amorphophallus rostratus
• Amorphophallus rugosus
• Amorphophallus sagittarius
• Amorphophallus salmoneus
• Amorphophallus saraburiensis
• Amorphophallus saururus
• Amorphophallus scaber
• Amorphophallus scutatus
• Amorphophallus sizemorae
• Amorphophallus smithsonianus
• Amorphophallus sparsiflorus
• Amorphophallus spectabilis
• Amorphophallus staudtii
• Amorphophallus stipitatus
• Amorphophallus stuhlmannii
• Amorphophallus subsymbiformis
• Amorphophallus sumawongii
• Amorphophallus sylvaticus
• Amorphophallus symonianus
• Amorphophallus synandrifer
• Amorphophallus taurostigma
• Amorphophallus tenuispadix
• Amorphophallus tenuistylis
• Amorphophallus teuszii
• Amorphophallus tinekeae
• Amorphophallus titanum : Titan Arum, Krubi (largest flower structure on earth)
• Amorphophallus tonkinensis
• Amorphophallus variabilis
• Amorphophallus venustus
• Amorphophallus verticillatus
• Amorphophallus yuloensis
• Amorphophallus yunnanensis : Kerri's Giant Arum
• Amorphophallus zengianus
• Amorphophallus zenkeri
  • Amorphophallus zenkeri subsp. mannii
  • Amorphophallus zenkeri subsp. zenkeri

References

1. ^ Robert L. Freedman, The famine foods database

• Hetterscheid, W.L.A. 1994. Preliminary taxonomy and morphology of Amorphophallus Blume ex Decaisne (Araceae). In: M.M. Serebreyanyi (ed.), Proc. Moscow Aroid Conference 1992: 35-48. Moscow.
• Hetterscheid, W.L.A. & G.J.C.M. v. Vliet, 1996. Amorphophallus, giant from the forest. CITES/C&M, 2(4): 86-96.
• Everything You Always Wanted to Know About Amorphophallus, but Were Afraid to Stick Your Nose Into!!!!! by Wilbert Hetterscheid and Stephen Ittenbach - Aroideana 19 :7-129

External links

• List of Amorphophallus species with photos from the International Aroid Society
• CATE genus page
• Amorphophallus in Brunken, U., Schmidt, M., Dressler, S., Janssen, T., Thiombiano, A. & Zizka, G. 2008. West African plants - A Photo Guide. Forschungsinstitut Senckenberg, Frankfurt/Main.