Palm trees

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Palm trees
Canary Island Date Palm (Phoenix canariensis)

Canary Island Date Palm ( Phoenix canariensis )

Systematics
Subdivision : Seed plants (Spermatophytina)
Class : Bedecktsamer (Magnoliopsida)
Monocots
Commelinids
Order : Palm- like arecales
Family : Palm trees
Scientific name
Arecaceae
Schultz Sch.

The palms or palms (Arecaceae or Palmae) are a family of the order of the palm-like (Arecales) within the monocotyledons (monocotyledons). Related species were widespread around 70 million years ago in the Cretaceous Period . The family contains 183 genera with about 2600 recent species .

The palm family includes the longest leaf (in palms of the genus Raphia with a length of up to 25 meters), the largest seed (from the Seychelles palm Lodoicea maldivica weighing up to 22 kilograms), and the longest inflorescence in the plant kingdom (in the Genus Corypha ) with a length of about 7.5 meters and an estimated 10 million flowers per inflorescence.

Description and ecology

Appearance

The representatives of the palm family are very diverse. They can be small, medium-sized or large (up to 60 m trunk height for the Quindio wax palm ), stand individually or in groups (clusters), are reinforced or unreinforced. They can bloom several times in a lifetime (pleonanth) or only once in a lifetime ( hapaxanth ).

The trunk is "lignified". It is slim to massive, very short to very high, it can be creeping, underground, climbing or upright. Usually the trunk is unbranched in the aboveground area, rarely it is dichotomously branched. The trunk lacks a cambium , so palms have no secondary growth in thickness , which is why they are not counted among the trees . In some palms, however, a diffuse growth in thickness occurs. The internodes are short to long. The leaf scars are conspicuous to inconspicuous. Some palms have stilt roots .

leaves

Coconut palm leaf ( Cocos nucifera )

The leaves are alternate and are in a spiral arrangement, rarely two-lined (distich). The leaf blade is initially always formed undivided, often it splits later. The leaves can be armed with spines or bristles, they are bare or variously covered with scales and / or hair. Sometimes they have a ligula- like appendage on both sides or in front of the petiole . The leaf sheaths sometimes form a crown shaft. The petiole is usually clearly developed. It is unreinforced or reinforced in various ways. A hastula can be formed or absent.

The shape of the leaf blade is fanned out (palmat, fan palm ), costapalmat, pinnate (pinnat), double-pinnate (bipinnat), two-part (bifid) or undivided, but then with pinnate-shaped veins. The leaf is folded in the bud. Later the blade tears either along the adaxial fold edges (induplicate) or along the abaxial edges (reduplicate). It seldom tears between the folds or does not tear at all. The resulting segments or leaflets are lanceolate or linear to rhombic or wedge-shaped. In cross-section, the leaflets are V-shaped in the induplicate leaves and A-shaped in the reduplicate leaves. They are single or multiple folded, usually they have a central rib and numerous parallel arteries. The segments seldom tear further between these secondary arteries. The blade can be hairy or scaled differently, spines and bristles are also present. The proximal leaflets can be transformed into thorns in climbing species ( acanthophylls ), the rachis can be transformed distally into a climbing aid ( tendril ) and can then also carry acanthophylls.

Generative characteristics

Male single flower of Jubaea chilensis
Coconut palm inflorescence ( Cocos nucifera )
Subfamily Coryphoideae Tribus Borasseae: fruits of Borassus akeassii

The flowers of the Arecaceae family are hermaphroditic or unisexual. The species are polygamous , monoecious, or dioecious .

The inflorescences are usually on the side (or less often on) the tip. If the inflorescence is at the tip of the palm (terminal = terminal), then the plant specimen dies after flowering and seed formation; these species are hapaxanth , i.e. perennial , all others are persistent. The mostly well-branched inflorescences are covered with a spathe as protection when they are in bud . The flowers can be hermaphroditic, but mostly they are unisexual. There are monoecious ( monoecious ) and dioecious ( dioecious ) palm species. The flowers are always threefold and are mostly radial symmetry , rarely the flower structure is screwy. There are usually three sepals and petals; they are free or overgrown. There are usually six, rarely fewer, stamens ; some of them are often reduced to staminodes . The three carpels can be completely free or grown together at their base. Each carpel contains one or two ovules . You can rarely see a stylus and so the three stigmas per flower are usually seated. The pollination is done by insects ( Entomophilie ) or by the wind ( anemophily ).

Palms form closing fruits , mostly hard berries or stone fruits . The pericarp is smooth, hairy, covered with spines or scales. The fruits usually contain one or two to three, only rarely up to ten seeds.

distribution

Palm species are distributed worldwide in tropical and subtropical areas. The greatest biodiversity is found in tropical rainforests; But palm trees also grow in some seasonal or semi-arid areas. An example of the latter is the palm-rich Cerrado in central Brazil.

In the north the area of ​​the palm trees extends to about 44 ° north latitude in southern France ( Chamaerops humilis ), in the south a little over 44 ° on the Chatham Islands near New Zealand ( Rhopalostylis sapida ). In North America, Sabal minor extends to almost 36 ° north latitude in North Carolina, Washingtonia filifera in California to 37 °. In South America, Jubaea chilensis reaches in Chile to 35 ° south latitude. On the Asian mainland, Nannorrhops ritchiana extends to about 34 ° north latitude in Afghanistan and Pakistan. In Australia, Livistona australis extends over 37 °, in Africa Jubaeopsis caffra to about 31 °.

Systematics

Illustration of Trithrinax brasiliensis
Subfamily Calamoideae tribe Lepidocaryeae: Raphia australis
Subfamily Calamoideae Tribus Lepidocaryeae: Buriti palm ( Mauritia flexuosa )
Subfamily Calamoideae tribe Calameae: Calamus rotang
Subfamily Nypoideae: Nipapalme ( Nypa fruticans )
Subfamily Coryphoideae tribe Sabaleae: Sabal uresana
Subfamily Coryphoideae tribe Cryosophileae: Thrinax radiata
Subfamily Coryphoideae Tribus Trachycarpeae: dwarf palm
( Chamaerops humilis )
Subfamily Coryphoideae Trachycarpeae: Trachycarpus martianus
Subfamily Coryphoideae tribe Trachycarpeae: Brahea armata
Subfamily Coryphoideae Trachycarpeae: California Washington Palm ( Washingtonia filifera )
Subfamily Coryphoideae tribe Caryoteae: Caryota rumphiana
Subfamily Coryphoideae Tribus Corypheae: Talipot palm ( Corypha umbraculifera )
Subfamily Ceroxyloideae tribe Ceroxyleae: Ravenea rivularis
Subfamily Arecoideae Tribus Roystoneae: Cuban Royal Palm ( Roystonea regia )
Subfamily Arecoideae tribe Cocoseae: Jubaea chilensis
Subfamily Arecoideae Tribus Cocoseae: peach palm ( Bactris gasipaes )
Subfamily Arecoideae Tribus Manicarieae: Manicaria saccifera
Subfamily Arecoideae tribe Euterpeae: Euterpe oleracea
Subfamily Arecoideae tribe Geonomateae: Geonoma pauciflora
Subfamily Arecoideae tribe Areceae: Archontophoenix alexandrae
Subfamily Arecoideae tribe Areceae: Betel nut palm ( Areca catechu )
Subfamily Arecoideae tribe Areceae: Verschaffeltia splendida
Subfamily Arecoideae tribe Areceae: Dictyosperma album
Subfamily Arecoideae tribe Areceae: Iguanura wallichiana

Taxonomy

The family name Arecaceae was validly published in 1820 by Friedrich von Berchtold and Jan Svatopluk Presl in O Prirozenosti Rostlin , p. 266. The type genus of Arecaceae Bercht. & J. Presl nom. cons. is Areca L. The family name Palmae was first published in 1789 by Antoine Laurent de Jussieu in Genera Plantarum , p. 37.

External system

The Arecaceae form a monophyletic group. They are the sister group of the Dasypogonaceae . These relationships were unclear for a long time and it was not until 2016 that the Dasypogonaceae were placed in the Arecales order with the Arecaceae .

Internal system

The systematics of the Arecaceae has been greatly changed by molecular genetic studies. In 2005 a classification of the family summarizing the various sub-works was published. This classification was adopted in Genera Palmarum in 2008 with updates.

The relationships between the five subfamilies have now been investigated quite well. They can be represented by the following cladogram :





Arecoideae


   

Ceroxyloideae



   

Coryphoideae



   

Nypoideae



   

Calamoideae


In 2016, Baker and Dransfield published a further update of the classification based on the following system:

  • Subfamily Nypoideae:
    • Nipa palm ( Nypa Steck )

use

food

The fruits of around 100 palm species are edible ( date palm , palmyra palm ), while the seeds of others ( coconut , betel nut , palmyra palm) are edible . The edible cone of vegetation is called the palm heart , and sago can be obtained from the pulp of the trunk of some species . In the Indomalayan region the sago palm is of great importance as a starch supplier. The sap of palm trees - especially the sugar palm - is used to make beverages, and sugar can also be extracted from it. By fermentation produced palm wine . Beverages can also be made by fermenting fruit pulp. Few palm blossoms attract bees, so palm honey is actually a palm syrup and is not produced by bees, but is made by boiling the palm sap, comparable to maple syrup . As an economically important oil producer, the oil palm from Africa is now cultivated in the tropics around the world.

construction materials

In many countries, palm species are the basic material for building houses, the trunks of which are used as wood and the water-repellent leaves are used for roofing ( palapa ). From Rotangpalmen ( Calamus ) are rattan -Furniture made.

Ornamental plants and erosion control

Palm species are used both as a style element to convey a southern impression in public green spaces and gardens and as indoor plants .

In areas with little rain they are used to stabilize the soil on embankments and (possibly irrigated) green spaces. They are also much less sensitive to wind breakage than deciduous trees, so they can thrive well in places exposed to wind.

swell

literature

  • David L. Jones: Palms. Könemann in Tandem Verlags-GmbH, 2002, ISBN 3-8290-4889-0 .
  • Frank O. Steeb: Palms. Portraits of the most famous species from all over the world. Mosaik Verlag GmbH, Munich 1993, book no. 03668.
  • Natalie W. Uhl, John Dransfield: Genera Palmarum: A Classification of Palms Based on the Work of Harold E. Moore, Jr. Genera Palmarum, 1987, ISBN 0-935868-30-5 .
  • William J. Baker, John Dransfield: Beyond Genera Palmarum : progress and prospects in palm systematics. In: Botanical Journal of the Linnean Society , Volume 182, Issue 2, October 2016. doi : 10.1111 / boj.12401

Individual evidence

  1. ↑ Article 18.5 International Code of Botanical Nomenclature 2006 , accessed on August 5, 2009.
  2. ^ P. Stevens: APWebsite , accessed November 29, 2009.
  3. ^ A b c d e 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. 136 f.
  4. ^ A b 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 , p. 105.
  5. ↑ a b Arecaceae at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed November 6, 2014.
  6. ↑ International Code of Botanical Nomenclature - (Saint Louis Code), Electronic version : Chapter III. Nomenclature of taxa according to their rank - Section 2. Names of families and subfamilies, tribes and subtribes - Article 18. Volltext-online oder online.
  7. ↑ a b c Craig F. Barrett, William J. Baker, Jason R. Comer, John G. Conran, Sean C. Lahmeyer, James H. Leebens-Mack, Jeff Li, Gwynne S. Lim, Dustin R. Mayfield-Jones , Leticia Perez, Jesus Medina, J. Chris Pires, Cristian Santos, Dennis Wm. Stevenson, Wendy B. Zomlefer, Jerrold I. Davis: Plastid genomes reveal support for deep phylogenetic relationships and extensive rate variation among palms and other commelinid monocots. In: New Phytologist , Volume 209, 2016, pp. 855-870. doi : 10.1111 / nph.13617
  8. ↑ The Angiosperm Phylogeny Group : An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV. In: Botanical Journal of the Linnean Society , Volume 181, 2016, pp. 1-20. doi : 10.1111 / boj.12385
  9. ^ John Dransfield, Natalie W. Uhl, Conny B. Asmussen, William J. Baker, Madeline M. Harley, Carl E. Lewis: A New Phylogenetic Classification of the Palm Family, Arecaceae. In: Kew Bulletin , Volume 60, 2005, pp. 559-569. JSTOR 25070242
  10. ^ 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. 138 f.
  11. ↑ Conny B. Asmussen, John Dransfield, Vinnie Deickmann, Anders S. Barfod, Jean-Christophe Pintaud, William J. Baker: A new subfamily classification of the palm family (Arecaceae): evidence from plastid DNA phylogeny. In: Botanical Journal of the Linnean Society. Volume 151, 2006, pp. 15-38. doi : 10.1111 / j.1095-8339.2006.00521.x
  12. ^ William J. Baker, John Dransfield: Beyond Genera Palmarum : progress and prospects in palm systematics. In: Botanical Journal of the Linnean Society , Volume 182, Issue 2, October 2016. doi : 10.1111 / boj.12401 doi : 10.1111 / boj.12401
  13. ↑ 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 Rafaël Govaerts (Ed.): Arecaceae. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 1, 2018.

Web links

Commons : Palms (Arecaceae)  - Collection of images, videos and audio files