Aruncus L.
Aruncus is native to the temperate and subarctic regions of the Northern Hemisphere. It is either considered a monospecific genus with one very variable species (Aruncus dioicus s.l.) or as a small genus with about three to six species. The latter taxonomic viewpoint probably prevails now (see for instance Cullen 1995, Cuizhi & Alexander 2003; see, however, Mabberley 2008, Mellichamp 2014). Some species are cultivated as ornamentals (e.g. Cullen 1995, Jäger & al. 2008).
In general appearance Aruncus is remarkably similar to Astilbe although the latter belongs to the Saxifragaceae family (see also Mellichamp 1977). Both genera are best distinguished by the number of stamens: respectively 20-30 versus 5-10.
Literature:
Cuizhi G. & Alexander C. (2003) Aruncus. In: Wu Z.Y. & Raven P.H. (eds.), Flora of China, vol. 9. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis: 74. [available online at: http://flora.huh.harvard.edu/china/PDF/PDF09/Aruncus.PDF]
Cullen J. (1995) Aruncus. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 4. Cambridge University Press, Cambridge: 342-343
Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.
Kurtto A., Lampinen R. & Junikka L. (eds.) (2004) Atlas Florae Europaeae. Distribution of Vascular Plants in Europe. 13. Rosaceae (Spiraea to Fragaria, excl. Rubus). The Committee for Mapping the Flora of Europe & Societas Biologica Fennica Vanamo, Helsinki: 320 p.
Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.
Mellichamp T.L. (1977) A comparative study of Aruncus (Rosaceae) and Astilbe (Saxifragaceae), and the problem of their relationships. Ph.D. dissertation, University of Michigan.
Mellichamp T.L. (2014) Aruncus. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 9. Oxford University Press, New York-Oxford: 422-424. [available online at: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=102737]
Potter D., Still S.M., Grebenc T., Ballian D., Božič G., Franjiæ J. & Kraigher H. (2007) Phylogenetic relationships in tribe Spiraeeae (Rosaceae) inferred from nucleotide sequence data. Pl. Syst. Evol. 266: 105-118. [available online at: http://www.academia.edu/4062516/Phylogenetic_relationships_in_tribe_Spiraeeae_Rosaceae_inferred_from_nucleotide_sequence_data]
Purohit K.M. & Panigrahi G. (1983) The genus Aruncus L. (Rosaceae) in India. Bangladesh J. Bot. 12(1): 11-18.
Tschalär Y. (1985) Biosystematische Untersuchungen in der Gattung Aruncus. Juris Druck und Verlag, Zürich: III + 107 p.
Weber H.E. (ed.) (1995) Rosaceae (p.p.). In: Illustrierte Flora van Mitteleuropa, vol. 4(2A) (3th ed.). Blackwell Wissenschafts-Verlag, Berlin: 235-659.