Amorphophallus

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Amorphophallus
Several Amorphophallus species

Several species of Amorphophallus
Systematics
Class : Bedecktsamer (Magnoliopsida)
Monocots
Order : Frog-spoon-like (Alismatales)
Family : Arum family (Araceae)
Subfamily : Aroideae
Genre : Amorphophallus
Scientific name
Amorphophallus
Flower ex decne.

Amorphophallus is a genus of plants withinthe Arum family (Araceae). The wide distribution area of ​​the approximately 200 species is the Paleotropic with Oceania , Africa and Asia . The titan arum ( Amorphophallus titanum ) has the largest " flower " in the world.

Description and ecology

Amorphophallus myosuroides tuber
Freshly sprouting Amorphophallus abyssinicus
Amorphophallus konjac inflorescence , cut open with female and male segments on the piston
Fruchtstand of Amorphophallus sylvaticus with berries at different stages
Split leaf blade of Amorphophallus sylvaticus
Vegetative phase of Amorphophallus bulbifer
Fruchtstand of Amorphophallus bulbifer

Appearance, persistence organs and leaves

Amorphophallus species grow as small to very large, seasonally green, perennial herbaceous plants . These geophytes form underground tubers as persistence organs , which in some species are lined up in several rows or rarely real, more or less creeping rhizomes . Some species form bulbils on the leaves for vegetative reproduction , either on the leaf surface, along the leaf hachis or between the two possibilities mentioned.

Each plant usually only produces one relatively large leaf during the growing season , rarely two or more. The leaves are clearly divided into a petiole and a leaf blade. The mostly upright, mostly bald, rarely hairy petiole is usually petiolate or rarely angular, slightly grooved or partially wrinkled in cross section. The more or less horizontal leaf blade is usually divided into three main segments. The main segments can be the same length or the upper one is shorter than the side segments. The bald rhachis leaf is narrow to broadly winged and often has many other leaflets.

Inflorescences, flowers and pollination

Depending on the season, a plant forms one, two to three or even more inflorescences to its side during or after the presence of the foliage leaf , one after the other or simultaneously. Amorphophallus species are single sexed ( monoecious ). The entire inflorescence acts as a flower biologically . The inflorescences have the structure typical of Araceae. On a more or less long inflorescence stem above a single bract, the spathe , a piston, the spadix.

The edges of the spathe are usually close together at their base. They are rarely open or overgrown. Depending on the species, the spathe is shaped differently and colored very differently on the outside.

The spadix begins directly above the spathe or slightly raised by a piece of the inflorescence axis. In the lower area of ​​the flask there is the female zone, which can pass directly into the male zone or both zones are separated by a sterile zone. The small, reduced, unisexual flowers sometimes have staminodes on their outer area , but never bracts . The female flowers contain only one pistil. The seated or shortly stalked ovary is one to vierkammerig (unlike Pseudodracontium with ever single-chamber ovary). There is only one ovule in each ovary chamber . A stylus is clearly present or hardly recognizable; it can be clearly demarcated from the ovary. If there is a sterile zone on the flask, it is usually covered with staminodes. This area is rarely partially or completely free of staminodes. The male zone is cylindrical, spindle-shaped, conical or inverted-conical. The male flowers usually contain three to six (one to eight) stamens . The short or elongated stamens have at most very short stamens that are free, partially or completely fused with one another. The dust bags have two counters. The spherical or elliptical pollen grains have no apertures. The spadix almost always ends in a sterile area which, depending on the species, is very different and sometimes very noticeable, sometimes with folds or crevices.

There are few scientific reports on the pollination of Amorphophallus species. Usually it is only observations of which insect species are in the inflorescences, but not what contribution they make to pollination. The spathe forms a cup-shaped base, which in some species can be interpreted as an insect trap. Some species actually use hair-like organs to prevent insects from climbing out. Keeping the pollinators trapped in the inflorescences is necessary for effective pollination. When the spathe, which protects the spadix when it is budding, opens, the female flowers are capable of being pollinated and must be pollinated on the same day. The open inflorescence gives off a lure scent, which is very different in the different species. In most species, the smell is unpleasant for humans after decay, death, manure and the like. Few species give off a pleasant smell of carrots, anise, chocolate, lemon or fruit for humans. This breadth of fragrances has been chemically analyzed. Simultaneously with the production of these fragrances, the spadix, mainly the upper area, warms up significantly and / or has an effect due to its infrared components. The dark brown to brownish purple parts of the inflorescence of some species look like decaying animals. Even hair on the top of the inflorescence in some species reinforces this illusion of dead animals. When the insects get inside the spathe, they migrate down to the female flowers and can deposit pollen from other inflorescences that cling to them. On this first day of the flowering period of an inflorescence, the male flowers are still closed. The insects should linger in the inflorescence until the male flowers open to pick up the pollen and transport it to other inflorescences. There are a few strategies to keep the insects lingering. For example, some Amorphophallus species provide food in the form of fleshy warts or staminodes that have been transformed into protein-rich food bodies. The uppermost area of ​​the spadix is ​​also such a source of food in some species. After pollen has adhered to the insects, they can leave the inflorescence.

Fruits and seeds

At the fruit cluster, the berries are close together or relatively far apart. The spherical, egg-shaped or narrowly elliptical berries usually turn orange to red, rarely blue or white, when ripe. and are mostly smooth or rarely warty; they contain one to four seeds. The seeds usually have a distinct raphe and they contain no endosperm . The berries are eaten by birds, but there are only a few reliable observations.

Systematics and distribution

The genus Amorphophallus was created in 1834 by Carl Ludwig Blume in Joseph Decaisne : Nouvelles Annales du Museum d'Histoire Naturelle , 3, p. 366 with the type species Amorphophallus campanulatus Blume ex Decne. set up. The scientific generic name Amorphophallus translates as “misshapen penis”. The genus Amorphophallus belongs to the tribe Thomsonieae in the subfamily Aroideae within the family Araceae . Synonyms for Amorphophallus Bl. Ex Decne. nom. cons. are: Allopythion Schott , Brachyspatha Schott , Candarum Schott nom. illeg., Conophallus Schott , Corynophallus Schott , Dunalia Montrouz. , Hansalia Schott , Hydrosme Schott, Kunda Raf. , Plesmonium Schott , Proteinophallus Hook. f. , Pseudodracontium N.E.Br. , Pythion Mart. nom. rej ., Pythonium Schott nom. illeg., Rhaphiophallus Schott , Synantherias Schott , Tapeinophallus Baill. , Thomsonia Wall. nom. rej.

The distribution area of Amorphophallus is palatropic . One finds species in tropical West to East Africa (including Madagascar), southern and southeastern to eastern Asia, northern Australia, on Pacific islands. There are 16 species in China, seven of them only there.

Inflorescence of Amorphophallus atroviridis
Inflorescence of Amorphophallus bulbifer
Inflorescences of Amorphophallus dunnii
Inflorescences of Amorphophallus konjac in culture
Vegetative stage in the culture of Amorphophallus napalensis with a stalked leaf with a split leaf blade
Vegetative stage of Amorphophallus paeoniifolius with stalked leaves with divided leaf blades
Inflorescence of Amorphophallus paeoniifolius
Amorphophallus prainii inflorescence
Vegetative stage of Amorphophallus rivieri with stalked leaves with divided leaf blades
Amorphophallus rivieri inflorescences
Illustration of Amorphophallus stuhlmannii
Titan arum ( Amorphophallus titanum ) with three inflorescences on May 14, 2006 in the Botanical Garden in Bonn
Illustration of Amorphophallus variabilis
Habitus and inflorescence of Amorphophallus variabilis from western Java
Illustration of Amorphophallus yunnanensis

There are about 200 types:

World records

A well-known species is the titan arum ( Amorphophallus titanum ), native to Sumatra (in a narrow distribution area about 1 ° north and south of the equator), whose inflorescence forms the largest flower in the plant kingdom from a flowering point of view . The piston of the inflorescence can reach a length of 1.50 meters. In the Bonn Botanical Garden it has already been possible to bring specimens to bloom several times. On May 23, 2003 a record was set by the 3.06 meter high titan arum inflorescence in the Botanical Gardens in Bonn. She has so although not the largest inflorescence in the world because the second longest with about 6 meters has the Palme Corypha Umbraculifera and the longest the bromeliad Puya raimondii with up to 8 meters in height. It is not even the largest flower , because this is what Rafflesia arnoldii produces .

use

Some Amorphophallus species are grown for food production, for example Amorphophallus aphyllus , Amorphophallus campanulatus , Amorphophallus consimilis , Amorphophallus dracontioides and Amorphophallus sylvaticus . Araceae species contain calcium oxalate crystals. If you eat fresh parts of plants, this substance is poisonous and is very unpleasant in the mouth, on the tongue and in the throat. But the problem of calcium oxalate can be solved by heating or drying. But people with rheumatism, arthritis, a tendency to develop kidney stones and over-acidity should be very careful with parts of plants that contain calcium oxalate.

The konjac root ( Amorphophallus konjac ) supplies tubers that are mainly used in Asia. The tubers are eaten cooked. After peeling, cooking and adding lime, the konjak flour, called "Konnyaku" in Japan, ( food additive E425) is obtained. Its carbohydrates are 80% indigestible and can therefore be used in diets.

Also Amorphophallus paeonifolius is particularly cultivated in India for food production. The rhizome has a diameter of up to 50 cm and is eaten fully cooked. The leaf stalks and leaf blades are also eaten after extensive cooking.

The medicinal effects of Amorphophallus paeonifolius and Amorphophallus konjac were studied. Amorphophallus konjac has insecticidal properties.

The titan arum ( Amorphophallus titanum ) is rarely used as an ornamental plant. Other species common among collectors are Amorphophallus albus , Amorphophallus bulbifer and Amorphophallus yunnanensis . These are also not quite as big and are easier to cultivate than Amorphophallus titanum . A closely related genus of tropical Africa is called Anchomanes , their leaf stalks are thorny.

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Individual evidence

  1. ↑ Amorphophallus at Tropicos.org. Missouri Botanical Garden, St. Louis
  2. ↑ Amorphophallus in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
  3. ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq br bs bt bu bv bw bx by bz ca cb cc cd ce cf cg ch ci cj ck cl cm cn co cp cq cr cs ct cu cv cw cx cy cz da db dc dd de df dg dh di dj dk dl dm dn do dp dq dr ds dt du dv dw dx dy dz ea eb ec ed ee ef eg eh ei ej ek el em en eo ep eq er es et eu ev ew ex ey ez fa fb fc fd fe ff fg fh fi fj fk fl fm fn fo fp fq fr fs ft fu fv fw fx fy fz ga gb gc gd ge gf gg gh gi gj gk gl gm gn go gp gq gr gs gt gu gv gw gx Rafaël Govaerts (Ed.): Amorphophallus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved May 30, 2019.
  4. ↑ Wilbert Hetterscheid: The Amorphophallus Species. Amorphophallus species list with links to species from the International Aroid Society . Last accessed on November 1, 2018.
  5. ↑ a b c d e f g h i j k l m n o p q Heng Li, Wilbert LA Hetterscheid: Amorphophallus. In: Wu Zheng-yi, Peter H. Raven, Deyuan Hong (Eds.): Flora of China . Volume 23: Acoraceae through Cyperaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 2010, ISBN 978-1-930723-99-3 , pp. 23 (English).
  6. ↑ The highest titan arum in the Bonn Botanical Garden.
  7. ^ Robert Freedman: Famine Foods - ARACEAE . ( Memento from December 21, 2009 in the Internet Archive )
  8. ↑ a b c Amorphophallus paeoniifolius at Plants For A Future
  9. ↑ a b c d Amorphophallus konjac at Plants for A Future . at Plants For A Future

Web links

Commons : Amorphophallus  - collection of images, videos and audio files