Dactyloctenium aegyptium

Dactyloctenium aegyptium (L.) Willd. (syn.: D. aegyptiacum (L.) Willd.) (subtrop. Afr., As.) – A very rare and ephemeral alien. Recorded but a few times so far in Belgium. First seen in Antwerp in 1882 between cobbles at the railway station Waes, subsequently in 1902 near the Red Star Line warehouse, also in Antwerp (Fasseaux 1951). In both localities the vector of introduction remained obscure. In 2016 rediscovered in Belgium after more than a century. A single individual was found between cobble stones near an abandoned grain mill in the Antwerp port area, along with several species that were clearly introduced with rice (Ammannia coccinea, Echinochloa oryzicola, Paspalum distichum and others). In the same year Dactyloctenium aegyptium was also seen by a railway track in Gent (Gentbrugge), obviously from discarded bird seed waste (along with Echinochloa frumentacea, Panicum miliaceum, Phalaris canariensis and other bird seed components). This species is known to occur as impurity in commercial bird seed mixtures (e.g. Hanson & Mason 1985, EPPO 2007).
In the latter locality Dactyloctenium aegyptium grows in an area where the superficially similar Eleusine tristachya also occurs and both species could be intermixed. Dactyloctenium is separated by its branches that are devoid of spikelets at their tips, while branches in Eleusine end in a spikelet.  
Some claims of Dactyloctenium aegyptium as wool alien from Belgium (e.g. Matagne 1943) were referable to the Australian D. radulans, a much more frequent wool alien. The latter has much shorter branches that are touching for most of their length (Fasseaux 1951, Nightingale & Weiller 2005).
Dactyloctenium aegyptium is increasingly recorded in southern Europe and seems to naturalize and expand locally, especially in sand dunes (e.g. Verloove & Sánchez Gullón 2008, Mifsud & Casha 2010). It is classified as high risk species for range expansion under climate change (Roger & al. 2015).

Selected literature:


Adu A.A., Yeo A.R. & Okusanya O.T. (1994) The response to salinity of a population of Dactyloctenium aegyptium from a saline habitat in southern Nigeria. Journal of Tropical Ecology 10(2): 219-228.
EPPO (2007) EPPO Reporting Service no. 06 – 2007. Pathway analysis: alien plants introduced through the bird seed pathway. Available online at: https://gd.eppo.int/reporting/article-1118.
Fasseaux W. (1951) Les Dactyloctenium adventices en Belgique. Bull. Soc. Roy. Bot. Belg. 84: 153-155.
Fisher B.S. & Schweickerdt H.G. (1941) A critical account of the species of Dactyloctenium Willd. in Southern Africa. Ann. Natal Mus. 10: 47-77.
Hanson C.G. & Mason J.L. (1985) Bird seed aliens in Britain. Watsonia 15: 237-252. [available online at: http://www.archive.bsbi.org.uk/Wats15p237.pdf]
Matagne H. (1943) Quelques phanérogames nouvelles pour la flore belge. Bull. Soc. Roy. Bot. Belg. 75: 123-131.
Mifsud S. & Casha A. (2010) Two new alien grasses from sand dunes of Ghadira Bay in Malta. The Central Mediterranean Naturalist 5(2): 6-9. [available online at: http://www.maltawildplants.com/publ/!pdf/Cenchrus_echinatus(Mifsud&Casha).pdf]
Nightingale M.E. & Weiller C.M. (2005) Dactyloctenium. In: Mallett K. (ed.), Flora of Australia, vol. 44B. Melbourne, ABRS / CSIRO Publishing: 315-320. 
Pringle J.S. (1985) Dactyloctenium aegyptium (Gramineae) new to Belize. Sida 11(2): 245. [available online at: http://www.biodiversitylibrary.org/page/10005925#page/253/mode/1up]
Roger E., Duursma D.E., Downey P.O., Gallagher R.V., Hughes L., Steel J., Johnson S.B. & Leishman M.R. (2015) A tool to assess potential for alien plant establishment and expansion under climate change. Journal of Environmental Management 159: 121-127. [available online at: http://www.sciencedirect.com/science/article/pii/S030147971530089X]
Ronsisvalle G.A. (1979) Nuova stazione di Dactyloctenium aegyptium (L.) Acherson & Graebner. Boll. Accad. Gioenia Sci. Nat. Catania, s. 4, 13(10): 5-8.
Sachdeva S.K. & Kals R. (1981) Cytologic, morphologic and chemotaxonomic studies in Dactyloctenium aegyptium (L.) Beauv. complex. Proc. Indian Acad. Sci., Pl. Sci. 90(3): 217-225.
Sánchez E. (1974) Anatomía foliar de las especies argentinas de los géneros Eleusine Gaertn. y Dactyloctenium Willd. Gramineae, subfamilia Eragrostoideae, tribu Eragrosteae. Darwiniana 18(3-4): 526-538.
Sharma B.M. & Chivinge A.O. (1983) Preliminary studies on the population differentiation in Dactyloctenium aegyptium (Linn.) P. Beauv. in Nigeria. Indian Forester 109(5): 267-279.
Sharma M.L. (1984) On the morphological differences between Dactyloctenium aegyptium and Dactyloctenium aristatum (Gramineae). Curr. Sci. 53(6): 326-327. [available online at: http://www.currentscience.ac.in/Downloads/article_id_053_06_0326_0327_0....
Sharma M. (1997) A new combination under Dactyloctenium aegyptium (Linn.) Willd. (Poaceae). Geobios New Rep. 16(1): 33-35.
Sharma M.L. & Salam A. (1984) Biosystematic survey of the Dactyloctenium aegyptium complex (Gramineae) in Punjab plains: 1. Cytotaxonomy. Res. Bull. Panjab Univ., Sci. 35(1-2): 139-146.
Sharma M.L. & Salam A. (1984) Biosystematic survey of the Dactyloctenium aegyptium complex (Gramineae) in Punjab plains. Res. Bull. Panjab Univ., Sci. 35(3-4): 7-11.
Verloove F. & Sánchez Gullón E. (2008) New records of interesting xenophytes in the Iberian Peninsula. Acta Botanica Malacitana 33: 147-167. [available online at: http://www.biolveg.uma.es/abm/Volumenes/vol33/vol33.html]

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith