Syagrus

Syagrus flexuosa

Syagrus is a native to South America and the Antilles palm genus. In shape and other features, the genus is very variable.

  • 5.1 Notes and references

Features

Syagrus is a very variable species. The palm trees are small to large, single-stemmed or standing in groups, rarely branched underground. They are unarmed or armed. They are several times flourishing and monoecious getrenntgeschlechtig ( monoecious ). The trunk can be very short and subterranean, or upright and tall. He rarely is stolon -like. Sometimes it is swollen at the base. The crown near the stem end is covered by the remains of leaf bases, the other parts are slightly striped and fitted with leaf scars that can be inconspicuously conspicuous, but also increased or depressed.

The chromosome number is 2n = 32

The leaves are pinnate and are available in a spiral arrangement. The leaf scars are circular and are available in five rows. The leaves fall off with a smooth scar or dead remain on the plant ( Marzeszenz ). The leaf sheath dissolves into a tangled mass of fibers. The petiole is very short to long, its edges are smooth or wear short fibers, rarely rough, prickly fibers. The leaf surfaces are bare, hairy, scaly or waxy. The rachis is straight or curved, short to long, and also scaly, hairy or bald. The few to very numerous leaflets are simply folded, and are regularly or irregularly arranged on the rachis. They are available in one or more planes. They are linear, stiff or bent, the peaks are sharp, pointed or blunt. The upper side of blade is busy glabrous or with few scales or hair, sometimes waxy. The underside is usually hairy conspicuous along the main nerve.

Inflorescences

The inflorescences are individually and between the sheets ( interfoliar ). They are rare ear of corn shaped, but usually simply branched. They are significantly shorter than the leaves. The peduncle is elliptical in cross-section, short or long, glabrous or hairy or scaly different. The cover page is mostly hidden within the leaf sheaths, Roehrig, flattened, zweikielig and torn at the top. With increasing age, there is fibrous and disintegrates. The bract on peduncle is persistent and significantly longer than the previous sheet. Usually it is directly above the cover page. It is Roehrig and closes the inflorescence until shortly before anthesis one. Very rarely is shorter than the inflorescence. It is often fusiform, before it ruptures along. It is mostly woody, rarely it is thin - leathery or papery.

The inflorescence axis is usually shorter than the stem or nearly equal length. She is bald or hairy and bears the flower-bearing lateral axes ( Rachillae ) in a spiral arrangement. Each Rachilla is in the armpit of a short, triangular, usually leathery liner sheet. The few to numerous Rachillae are short or long, slender, straight or often rotated in the bud, often zigzag. You are bald or slightly hairy. At the Rachilla are in a spiral arrangement of the flowers triads, in the distal portions are paired or single male flowers. The flowers groups are usually sitting in the armpit of an inconspicuous supporting sheet. The flowers are tiny - Brakteolen.

Flowers

The male flowers are usually asymmetrical. The three sepals are triangular, and imbricat free or shortly fused together. Rarely they have grown into a stem-like base. The three petals are free, valvat and thin - leathery or fleshy. They are much longer than the sepals, their shape is lanceolate, oblong or oval with a pointed end. You are bald, hairy, scaly or dotted. The six stamens have filaments free, or they are grown short. The filaments are short and fleshy. The anthers are oblong, dorsifix near the base or Medifix. You are latrors or intrors. The stamp rudiment is very small or missing. The pollen is ellipsoidal, often pear-shaped, often slightly to distinctly asymmetrical. The germ is opening a distal sulcus.

De female flowers can be a bit smaller to much larger than the male flower. The three sepals are free, wide imbricat, triangular to ovate, acute to obtuse, fleshy to leathery, and sometimes hairy or scaly. The three petals are free, easy shorter to slightly longer than the sepals. They are triangular to oval, wide at the base imbricat and have small to medium-sized and striking valvate tips. The staminodes ring is membranous, flat and nearly hexadentate. The gynoecium is columnar to conical or ovoid and has three compartments with one ovule. The surface of the ovary is glabrous or hairy to scaly, the three stigmas are bent back and fleshy. The ovules are sitting on the side of the central wall compartments.

Fruits

The fruits are often similar to those of the coconut palm and are often edible. They are small to quite large and each contain one, rarely two seeds. They are spherical, ovoid, or ellipsoidal and of green, brown, yellow or reddish color. Some fruits are beaked. The perianth and the Staminodienring remain at the base and sometimes enlarge into a cupula. The exocarp is smooth or longitudinally striped, glabrous or hairy. The mesocarp is fleshy or dry and has numerous longitudinal fibers. The endocarp is thick, woody and carries three (rarely four) basal pores. The endocarp - cavity is irregularly shaped or more often circular, rarely triangular in cross-section with three eye-catching, senkreckten lines. The seed corresponds to the shape of the Endokarphöhle, is subbasal against the fruit. The endosperm is homogeneous or ruminat and sometimes has a central cavity. The embryo is basal or subbasal opposite one of the endocarp pores.

Dissemination and locations

The genus is restricted to South America with one exception. Here she comes from Venezuela south to Argentina before. Most species in this case has Brazil. One species is found in the Lesser Antilles.

Most species are restricted to arid and semi-arid areas, among them all stemless species. A few species, mainly the tree-like, are limited to mesische to tropical rain forests. The stemless species are characteristically part of several Brazilian arid vegetation types, such as Cerrado or Campo rupestre.

System

The genus Syagrus is provided Attaleinae within the palm family in the subfamily Arecoideae, Tribe Cocoseae and subtribe. Closely related genera within this subtribe are Lytocaryum and Attalea. The genus is probably polyphyletic, but a detailed phylogenetic study of Attaleinae missing.

In Brazil, where several species occur in sympatry, to form natural hybrids. Where in culture Syagrus and Butia capitata romanzoffiana grow together, also form hybrids.

In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew, the following species and hybrids are recognized:

  • Syagrus amara
  • Syagrus botryophora
  • Syagrus campestris
  • Syagrus campylospatha
  • Syagrus cardenasii
  • Syagrus cearensis
  • Syagrus cocoides
  • Syagrus comosa
  • Syagrus coronata
  • Syagrus x costae
  • Syagrus duartei
  • Syagrus evansiana
  • Syagrus flexuosa
  • Syagrus glaucescens
  • Syagrus glazioviana
  • Syagrus graminifolia
  • Syagrus harleyi
  • Syagrus inajai
  • Syagrus lilliputiana
  • Syagrus loefgrenii
  • Syagrus macrocarpa
  • Syagrus × matafome
  • Syagrus mendanhensis
  • Syagrus microphylla
  • Syagrus oleracea
  • Syagrus orinocensis
  • Syagrus petraea
  • Syagrus picrophylla
  • Syagrus pleioclada
  • Syagrus pseudococos
  • Syagrus romanzoffiana
  • Syagrus ruschiana
  • Syagrus sancona
  • Syagrus schizophylla
  • Syagrus smithii
  • Syagrus stenopetala
  • Syagrus stratincola
  • Syagrus × teixeiriana
  • Syagrus × tostana
  • Syagrus vagans
  • Syagrus vermicularis
  • Syagrus werdermannii
  • Syagrus yungasensis

The genus name Syagrus was already used in ancient times for a palm tree, so by Pliny, but not for the now so called New World genus. The genus was first described by Carl Friedrich Philipp von Martius in 1824, the type species is Syagrus cocoides. In the past, today counted to Syagrus species were divided into several classes, which were separated from Syagrus due to their ruminaten endosperm. However, this has proven to be unreliable distinguishing feature. With the first edition of Genera palmarum 1987, the species of these genera were asked to Syagrus. A study of the tribe Cocoseae 2004 showed that Syagrus is polyphyletic. Since in this work, only three species of the genus, however, were represented, the demarcation of a monophyletic genus Syagrus and a spin-off of new species is not possible.

Use

The leaves of several species are used for palm leaf roofs, from the leaves of Syagrus coronata wax is obtained. The mesocarp of Syagrus oleracea and Syagrus coronata is edible, from the endosperm of Syagrus coronata, a cocoides and Syagrus palm oil are obtained. The wood of the stems is often used. Several species are used as ornamental plants.

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. 423-428.
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