Iriartea

Iriartea deltoidea

Iriartea deltoidea is a South American species of palm. It is the only species of the genus Iriartea and named after the Spanish diplomat Bernardo de Iriarte ( 1735-1814 ).

• 5.1 Notes and references

Features

Iriartea deltoidea is an often very large, single -stemmed and monoecious palm. The trunk is occupied upright, often bulbous and with conspicuous annular leaf scars. Reaching up to 25 m in height with a diameter of 10 to 30 cm. Up to 100 slender stilt roots form a dense cone that covers the base of the trunk. The stilt roots are up to 2 m long and 3.5 cm thick and covered with spines.

The chromosome number is 2n = 32

The palm tree is quite a few leaves, usually 4 to 7 These are pinnate and fall off with a smooth scar. The leaf sheaths form a well-marked, 60 to 150 cm long crown stem. The petiole is rather short, on the upper side has a groove and is rounded at the bottom. The rachis is at the top in shape and rounded at the bottom, and from 2 to 4.3 meters long. The leaflets are large, asymmetrical rhombic ( deltoid, hence the name), elliptic to. The petiole closer ( proximal ) edge of the sheet is in the lower third of entire, dentate then pulled out. The distal leaf margin is entire, shorter and then perforated torn. All the leaflets is itself irregular split in linealische segments that are in different planes, giving the leaf a fiederiges appearance.

Inflorescences

The inflorescences are individually and under the leaves ( infrafoliar ). They depend, to 2 m long and are strongly curved in bud stage. You are branched once or twice, the male flowers open first ( Proterandrie ). The peduncle is thick and round in cross section. The cover sheet is short, Roehrig, zweikielig and open at the top. There are 8 to 12 bracts on the inflorescence stalk. They are spirally, are Roehrig, envelop the inflorescence and leave after dropping showy, almost annular scars. The inflorescence axis is the same length as or slightly longer than the stem, she is wearing spiral standing, small, collar-like bracts. The first-order lateral axes are finger-shaped branches in the distal region of the inflorescence, unbranched at the top of the inflorescence. They are very long and have a spiral arrangement of flowers triads. At the top of these axes are reduced to single or paired male flowers.

Flowers

The male flowers are approximately symmetrical. The three sepals are not adherent, rounded, imbricat. The three petals are three to four times as long as the calyx, valvat, boat -shaped and curved. There are 9 to 20 stamens with very short filaments and snakes, long anthers. The stamp rudiment is very small or absent altogether. The pollen is ellipsoidal and more bisymmetrical. The germ is opening a distal sulcus. The longest axis measures 31 to 35 microns.

The female flowers are smaller than the male. The three sepals are free and widely overlapping. The three petals are also free, broad, rounded, imbricat with the exception of the triangular valvaten tips. The up to 12 staminodes are very small and tooth-shaped. The gynoecium is spherical, dreifächrig with three ovules and three scars. It usually ripens only one ovule to seed.

Pollination is by bees.

Fruit and seeds

The fruit is usually round, to mature yellow and has a diameter of 2 to 2.8 cm. The scars remaining at the forefront. The exocarp is smooth, the mesocarp grained and fibrous, endocarp very thin. The seed is globular, sitting basal. The scar ( hilum ) is circular, the endosperm is homogeneous.

Dissemination and locations

Iriartea deltoidea comes from Costa Rica and Nicaragua south to Colombia, Ecuador, Peru, Bolivia, Venezuela and Brazil before. To the east, their distribution is limited to the western Amazon basin.

It grows in tropical lowland rain forest and in lower elevations of the mountain rainforest. Rarely it is to find over 1300 m above sea level. It grows on slopes and hilltops in the lowland and on flat ground. At the bottom it makes no special claims. To the east of its range it is attached to the edge of rivers. The annual rainfall is mostly between 2000 and 3000 mm, the focus of their distribution is likely to be in areas with more than 2500 mm.

The focus of their geographical distribution, the eastern slopes of the Andes at altitudes between 300 and 1200 m. At lower altitudes, it is much rarer.

System

The genus Iriartea is placed in the subfamily Arecoideae, Tribe Iriarteeae within the family Arecaceae. The relationships within the tribe are not released. Three studies came to conflicting results in each case.

In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew, just the way Iriartea deltoidea is recognized.

Use

The outer part of the stem is very hard. It is used for house construction and for the manufacture of spears. After Alfred Russel Wallace ( 1853), the bulbous parts of the strains are used for canoes. In the Choco region of Colombia coffins are made from the trunks.

Documents

• John Dransfield, Natalie W. Uhl, Conny B. Asmussen, William J. Baker, Madeline M. Harley, Carl E. Lewis: Genera palmarum. The Evolution and Classification of Palms. Second edition, Royal Botanic Gardens, Kew 2008, ISBN 978-1-84246-182-2, pp. 362-364.