African pennon cleaner grass

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African pennon cleaner grass
Fountain Grass (30980302392) .jpg

African pennon cleaner grass ( Cenchrus setaceus )

Systematics
Commelinids
Order : Sweet grass (Poales)
Family : Sweet grasses (Poaceae)
Subfamily : Panicoideae
Genre : Cenchrus
Type : African pennon cleaner grass
Scientific name
Cenchrus setaceus
( Forssk. ) Morrone

Cenchrus setaceus , also known as African pennon cleaner grass as a garden plant, is a species fromthe sweet grass family (Poaceae). The species was until recently in the, now discontinued, the genus Pennisetum ( Pennisetum provided) and is still in numerous publications under the synonymous scientific name Pennisetum setaceum listed. Originally native to North and East Africa and the bordering West Asia, the species was introduced as an ornamental grass to numerous other regions with a subtropical climate, where it has become wild and has developed into an invasive species . The species is onthe European Union's list of invasive alien species of Union concern .

description

Clumps of the African pennon cleaner grass on the island of La Palma, Canary Islands

Cenchrus setaceus is a perennial , sometimes only annual, clump-forming grass species that can also develop underground creeping shoots ( rhizomes ). The upright stalks reach a stature height of about 20 to 130 centimeters, in favorable locations, for example in well-watered gardens, even above. They are woody at the base . The leaves are both basal and at the nodes of the stalk, the leaf blade, rolled when young, is about (10-) 20 to 30 (- 80) cm long and 1 to 3 mm wide, it is a little blue-green in color and long ciliate at the edge, with a noticeably protruding midrib on the upper side of the blade, it is longer than the associated internode. The leaf sheaths and internodes are smooth, the ligule replaced by a corona.

The 6 to 30 centimeters long inflorescences , which give the common name its name, are false spikes in which the partial inflorescences ( spikelets ) are densely packed. Each spikelet consists of a sessile and usually one (rarely two or none) stalked flowers . The spikelets are 4.5 to 6.5 mm long, lanceolate and laterally flattened, all glumes without awns. They are surrounded at the base by a wreath of very long and conspicuous hair bristles, which are feathered at least at their base. These are unequal to each other, the longer reach about 40 mm in length.

Similar species

Forms with a burgundy-red leaf blade are known mainly from gardens, usually referred to as forma rubrum . These were separated from the botanists Joseph K. Wipff and Jan-Frits Veldkamp as a separate species Pennisetum advena , today Cenchrus advena . However, this is not recognized by all taxonomists. Cenchrus longisetus and Cenchrus orientalis are also very similar ; they can be distinguished primarily by the length distribution of the bristle hairs.

Phylogeny and Taxonomy

The species was first described by the Swedish naturalist Peter Forsskål in the text Flora Aegyptiaco-Arabica (published posthumously in 1775) under the Basionym Phalaris setacea , Forsskål discovered it in Egypt on a research trip to Egypt and Arabia financed by the Danish king, on which he in 1773 Yemen died of malaria. In 1923 the Italian botanist Emilio Chiovenda transferred it to the genus Pennisetum described by Louis Claude Marie Richard in 1805 , in which it remained unchallenged until the 2010s. A common synonym is Cenchrus asperifolius Desf. (= Pennisetum asperifolium (Desf.) Kunth ).

Pennisetum was distinguished from the genus Cenchrus already described by Carl von Linné on the basis of the free hair- shaped bristles (in Cenchrus connected at the base and scaly or pungent bristles ). Long-standing difficulties in assigning individual species to one of these genera then led, on the basis of phylogenomic studies, to the finding that the species of the species-poor genus Cenchrus are nested in the genus Pennisetum and not closely related to each other, especially Cenchrus setaceus turned out to be closer to the most of the previous Cenchrus species are related than to those previously identified according to Pennisetum , whereby an emergence of the species through an earlier hybridization involving a Cenchrus species with polyploidization of the genome was made probable. For the now required common genus, the older name Cenchrus had to be used according to the nomenclature rules , although the earlier genus Pennisetum was much more species-rich, the species was therefore recombined by Osvaldo Morrone in his work (from 2010) to Cenchrus setaceus . The new position quickly established itself in the professional world, but the older name Pennisetum setaceum can still be found in most applied works, in horticulture and also in the text of the European Union regulation .

Common name

The common name "African" pennon cleaner grass was chosen by gardeners to distinguish the species from the ("Australian") pennon cleaner grass ( Cenchrus purpurascens Thunb. , Formerly mostly Cenchrus alopecuroides (L.) Thunb. Or Pennisetum alopecuroides (L.) Spreng. ). It was not chosen quite happily, because numerous other species of the genus with very similar morphology, but which are not used for horticulture, are also at home in Africa.

Use as a garden plant

The African pennon cleaner grass is a popular species of ornamental grass that is valued as a solitary shrub and in borders , primarily because of its decorative false spikes. Common varieties are 'Astrosanguineum', 'Cupreum', 'Rubrum' (leaves purple-red with green approaches to red-brown), 'Fireworks' (leaves bright red) and 'Purple Majesty' (leaves red, annual). The species belonging to the gardener names Pennisetum 'purpureum' and Pennisetum 'rubrum' is disputed (see below), but they were traditionally considered to belong to this species until the species was included in the list of invasive alien species.

More recently, the Central Horticultural Association has advocated that the red-leaved form of the African pennon-cleaner grass, previously known as Pennisetum setaceum 'Rubrum', does not actually belong to this species; they refer to a work by the botanists Wipff and Veldkamp and information in letters from the American botanist and Grass specialist Joseph Wipff himself. The background to this is the inclusion of the species on the list of invasive alien species of Union-wide importance on July 12, 2017 , which means that further trade is prohibited (with a one-year transition period). The Management Committee on Invasive Species of the EU member states therefore decided on December 5, 2017 that they are initially not subject to the EU regulations on invasive species. The handling of the authorities in the matter has so far been inconsistent. Cultivars sold under the name African pennon cleaner grass are at least apparently tolerated so far.

Spread, invasive species

The African pennon cleaner grass is native to arid , subtropical regions, especially on the North African coast of the Mediterranean and the adjacent Sahara region, in the Levant and in Arabia. It is planted as an ornamental grass in regions with similar climatic conditions, for example in the entire Mediterranean region, in the west of the USA, in South Africa and Australia, has become wild here and is now considered an invasive species. But it is ecologically more plastic, in the garden it can be used up to winter hardiness zones 7 to 10 and is therefore a popular ornamental plant in Central Europe as well. Unlike in warmer climates, however, it has not yet grown wild here, naturalized occurrences are known neither in Austria nor in Germany.

The species is able to build up considerable biomass in arid habitats with little vegetation cover . This is a fire ecology problem in particular . The biggest problems are in Hawaii , where grass has largely displaced the indigenous, fire-tolerant grass species Heteropogon contortus . Due to the higher aboveground biomass, the likelihood of fires has risen sharply in the new stocks. Similar fire problems are reported for the southwestern United States, such as the Sonoran Desert in Arizona and South Africa.

In the Mediterranean region, the species is currently spreading massively in Spain (including the Canaries), in southern France and in Italy. The species is unpopular as pasture grass and thus devalues ​​pastures, and there are similar problems with increasing tendency to burn, especially in the winter months. A difference in the invasiveness between the different cultural groups, including the red colored ones that are often separated, cannot be ascertained here.

Individual evidence

  1. ↑ a b Kamal M. Ibrahim, Hasnaa A. Hosni, Paul M. Peterson (2016): Grasses of Egypt. Smithsonian Contributions to Botany 103. x + 201 pages, 292 figures, 1 table.
  2. ↑ Shamin A. Faruqi (1980): Studies on Libyan Grasses VI. An Annotated Catalog and Key to the Species. Willdenowia 10 (2): 171-225.
  3. ^ Pennisetum setaceum (Forssk.) Chiov. . Flora Zambesiaca volume: 10 part: 3 (1989) Gramineae, by WD Clayton online Kew Databases, Royal Botanic Gardens, Kew.
  4. ↑ a b c J.K. Wipff, JF Veldkamp (1999): Pennisetum advena sp. nov. (Poaceae: Paniceae): a common ornamental throughout the southern United States. Sida 18: 1031-1036.
  5. ↑ a b Jan-Frits Veldkamp (2014): A revision of Cenchrus incl. Pennisetum (Gramineae) in Malesia with some general nomenclatural notes. Blumea 59: 59-75. doi: 10.3767 / 000651914X684376
  6. ↑ Jan-Frits Veldkamp (2015): Lectotypification of the fountain grass Cenchrus setaceus (Poaceae: Paniceae). Phytotaxa 218 (2): 171-176. doi: 10.11646 / phytotaxa.218.2.7
  7. ↑ M. Amelia Chemisquy, Liliana M. Giussani, Maria A. Scataglini, Elizabeth A. Kellogg, Osvaldo Morrone (2010): Phylogenetic studies favor the unification of Pennisetum, Cenchrus and Odontelytrum (Poaceae): a combined nuclear, plastid and morphological analysis , and nomenclatural combinations in Cenchrus. Annals of Botany 106: 107-130. doi: 10.1093 / aob / mcq090
  8. ^ AS Hitchcock: Manual of the Grasses of the United States, Volume 2. 2nd edition 1971, revised by Agnes Chase. Dover Publications, New York. ISBN 978-0-4863-1725-0 . as Pennisetum setaceum on p. 729.
  9. ↑ a b A.J. Oakes: Ornamental Grasses and Grasslike Plants. Van Nostrand Reinhold, New York 1990. ISBN 978-1-4684-1475-8 . as Pennisetum setaceum on pp. 256-258.
  10. ↑ Pennisetum setaceum on www.artensteckbrief.de, MultiBaseCS authority solutions for species protection. 34u GmbH.
  11. ↑ Zentralverband Gartenbau eV: Pennisetum setaceum 'Rubrum' is not invasive. ZVG calls for clarification from the EU. Press release No. 33/2017, November 20, 2017.
  12. ↑ But ban on African pennon cleaner grass . Article, Merkur online, updated October 5, 2017.
  13. ↑ Pennisetum setaceum - Red pennon cleaner grass . www.neobiota-austria.at, Neobiota in Austria. The influence of alien species on genes, species, and ecosystems. published by the Federal Environment Agency
  14. ↑ Stefan Nehring and Sandra Skowronek: The invasive alien species of the Union list of Regulation (EU) No. 1143/2014. First update 2017. BfN-Skripten 471. published by the Federal Agency for Nature Conservation, Bonn, 2017. ISBN 978-3-89624-208-2 , doi: 10.19217 / skr471 , pp. 66–67.
  15. ↑ Erin Goergen & Curtis C. Daehler (2000): Reproductive Ecology of a Native Hawaiian Grass (Heteropogon contortus; Poaceae) versus Its Invasive Alien Competitor (Pennisetum setaceum; Poaceae). International Journal of Plant Sciences 162 (2): 317-326.
  16. ↑ David G. Williams & Zdravko Baruch (2000): African grass invasion in the Americas: ecosystem consequences and the role of ecophysiology. Biological Invasions 2: 123-140.
  17. ↑ SJ Rahlao, SJ Milton, KJ Esler, B. van Wilgen, P. Barnard (2009): Effects of invasion of fire-free arid shrublands by a fire-promoting invasive alien grass (Pennisetum setaceum) in South Africa. Austral Ecology 34: 920-928. doi: 10.1111 / j.1442-9993.2009.02000.x
  18. ^ S. Brunel, G. Schrader, G. Brundu, G. Fried (2010): Emerging invasive alien plants for the Mediterranean Basin. EPPO Bulletin 40: 219-238.

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