Alocasia macrorrhizos

Riesenblättriges Arrow Sheet ( Alocasia macrorrhizos )

The Riesenblättrige Arrow Sheet ( Alocasia macrorrhizos ), also giant taro or Alokasie called, is a flowering plant in the genus of the arrow leaves ( Alocasia ) from the family of the Araceae ( Araceae ). In Spanish-speaking countries (eg Cuba, but there malanga, Xanthosoma violaceum Schott morada for ) this type is called Malanga.

• 6.1 Notes and references

Description

Appearance and foliage leaf

The Riesenblättrige Arrow leaf is a large, massive, evergreen, perennial herbaceous plant that reaches the stature heights of up to 4 meters. It contains a slightly milky white. The rhizomes are upright. It forms an upright, thick stem, which is up to 1.5 meters long.

There are always together several alternate permanent leaves, initially basal and in older plants at the end of the stem. The Riesenblättrige arrow sheet has the largest non- compound leaves of all plants; the largest composite sheets can be found in the palm Raphia farinifera. The leaves are divided into leaf sheath, petiole and leaf blade. From up to 1.3 meters long petiole lower third to half of the leaf sheath. The more or less upright, simple leaf blade is ovate - arrow-shaped, blunt triangular with a length of 1.2 meters and a width of 0.5 meters. Leaves on young plants can be weak shield-shaped ( Peltatum ). The leaf margin is straight to slightly wavy. On each side of the main Nerves are about nine lateral nerves of the first order.

Inflorescence and flower

The Riesenblättrige arrow sheet is monoecious getrenntgeschlechtig ( monoecious ). In the axils two inflorescences are formed via membranous Cataphyllen most. It is a beginning the Cataphylle hardly superior, later verlängender non exfoliated inflorescence stem available.

As is customary in the arum family consists of the inflorescence of a single bract ( spathe ) and the piston ( spadix ). The 13 to 35 cm long spathe is constricted from their base of Einsechstel to their length. The bottom of the spathe is green and ovate. The top of the pale yellow, with a length of 10.5 cm to 29 cm wide oblong- lanceolate spathe is after the open hood-like and bends back the withering and wilting. The spadix is slightly shorter than the spathe. The female - tapered zone is cylindrical with a length of 1 to 2 cm and a diameter of about 1.5 cm. The light green stamp has a diameter of about 3 mm. The seated scar is yellow and three to five lobes. The sterile zone has about the same dimensions as the female zone and is white. The orthorhombic hexagonal Synandroden have a diameter of about 2.5 mm. Male zone is white and cylindrical with a length of 3 to 7 cm and a diameter of about 2 cm. The male flowers are five-to neunzählig and with a diameter of about 2 mm rhombic- hexagonal with a convex top. The least half the length of the spadix upper flowerless zone is yellowish and runs slowly pointed.

Inflorescence and fruit

During fruit ripening, the spathe is green and with a length of about 8 cm oblong- ellipsoid. The ellipsoid with a length of about 12 mm and a diameter of about 8 mm berries are stained scarlet red when ripe.

Ecology

Caterpillars of the butterfly Cruria donowani (Lepidoptera: Agaristidae ) eat at Riesenblättrigen arrow sheet.

Use

The Riesenblättrige arrow sheet is used as food. It will be mainly used the starchy rhizomes and aerial parts of the stem axis. They are cooked like potatoes. They contain many minerals, vitamins A, B and C parts of plants may be eaten cooked, for uncooked mouth and esophagus are highly stimulated.

The sap is applied externally can be a powerful antidote to the very painful swelling caused by contact with the occurring in the Pacific tree-like plant nettle ( Urticaceae ) Dendrocnide gigas may arise.

Occasionally the Riesenblättrige Arrow leaf is also used as an ornamental plant in tropical gardens and as a houseplant.

Dissemination

The original home of Alocasia macrorrhizos can not be proven with certainty, it could well be Indonesia, Malaysia, Philippines and the Solomon Islands. As a major food crop, it was already used in prehistoric times in many parts of tropical Asia. Today, the Riesenblättrige Arrow leaf is spread with varieties in tropical areas around the world, as a crop and wild. It prefers moist locations.

System

The first publication of the Riesenblättrigen arrow sheet was already in 1753 by Carl Linnaeus in Species plantarum, macrorrhizon 2, page 965, under the name of Arum. The currently valid name Alocasia MacroRhizon she received in 1839 by George Don in junior Robert Sweet: Hortus Britannicus, 3rd edition, published S. 631.

There are many synonyms for Alocasia macrorrhizos (L.) G.Don known: Arum macrorrhizon L., Alocasia cordifolia ( Bory ) Cordemoy, Alocasia grandis NEBrown 1886 not 1868 Clemenceau, Alocasia indica ( Lour. ) Spach, Alocasia indica var diversifolia Engler, Alocasia indica var heterophylla Engler, Alocasia indica var metallica (Schott) Schott, Alocasia indica var rubra ( Hassk. ) Engl, Alocasia indica var variegata ( K.Koch & CDBouché ) Engl, Alocasia marginata NE Brown, Alocasia metallica Schott. Alocasia pallida K.Koch & CDBouché, Alocasia plumbea ( K.Koch ) Van Houtte, Alocasia uhinkii Engl & K.Krause, Alocasia variegata K.Koch & CDBouché, Arum cordifolium Bory, Arum indicum Lour. , Arum mucronatum Lam. Arum peregrinum L., Caladium indicum ( Lour. ) K.Koch, Caladium macrorrhizon (L.) R.Br., Caladium metallicum (Schott ) Engl, Caladium odoratum Loddiges not Ker Gawler 1820 1822 Caladium plumbeum K.Koch, Calla badian Blanco, Blanco Calla maxima, Colocasia boryi Kunth, Colocasia indica ( Lour. ) Kunth, Colocasia indica var rubra Hassk. , Colocasia macrorrhizos (L.) Schott, Colocasia mucronata ( Lam.) Kunth, Colocasia peregrina (L.) Raf., Colocasia rapiformis Kunth, Philodendron peregrinum (L.) Kunth, Philodendron punctatum Kunth.

Swell

• Heng Li & Peter C. Boyce: Alocasia: Alocasia macrorrhizos on page 77 - Online, 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. (Section Description, distribution, systematics and use)