Sorbus

In today's world, Sorbus is a highly relevant issue that impacts numerous people in different walks of life. Whether in the professional, personal or academic field, Sorbus has generated great interest and debate, awakening the curiosity of many. This phenomenon has gained greater importance in recent years due to its impact on society and its influence on decision-making. This is why it is essential to deepen our knowledge about Sorbus and its implications, in order to better understand its scope and find possible solutions to the challenges it poses.

Sorbus
European rowan (Sorbus aucuparia) with fruit
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Rosaceae
Subfamily: Amygdaloideae
Tribe: Maleae
Subtribe: Malinae
Genus: Sorbus
L.
Subgenera
Diversity
105 species

Sorbus is a genus of over 100 species of trees and shrubs in the rose family, Rosaceae. Species of Sorbus (s.l.) are commonly known as whitebeam, rowan, mountain-ash and service tree. The exact number of species is disputed depending on the circumscription of the genus, and also due to the number of apomictic microspecies, which some treat as distinct species, but others group in a smaller number of variable species. Recent treatments[1][2][3][4] classify Sorbus in a narrower sense to include only the pinnate leaved species of subgenus Sorbus, raising several of the other subgenera to generic rank.

Sorbus is not closely related to the true ash trees which belong to the genus Fraxinus, although the leaves are superficially similar.

Genus

As treated in its broad sense, the genus was traditionally divided into several subgenera, however, this treatment was found to be paraphyletic, being comprised of two disparate lineages within the Malinae subtribe. Consequently, each of the former subgenera have since been elevated into genera in their own right, with the genus name Sorbus retained only for the rowans. Additionally, it was recognised that despite a comparably large genetic distance between them, the genera Sorbus (sensu stricto), Aria, Chamaemespilus and Torminalis have interbred extensively, in various combinations, which lead to the recognition of an additional five intergeneric hybrid genera.[5]

Sorbus (Sorbus)
  • now genus Sorbus s.s., are commonly known as the rowan (primarily in the UK) or mountain-ash (in Ireland, North America and the UK), with compound leaves usually hairless or thinly hairy below; fruit carpels not fused; the type is Sorbus aucuparia (European rowan). Distribution: cool-temperate Northern Hemisphere.
Sorbus (Aria)
  • now genus Aria and its intergeneric hybrids (see below), the whitebeams, with simple leaves usually strongly white-hairy below (hence the name, from German Weissbaum, 'white tree'); fruit carpels not fused; the type is Aria edulis (common whitebeam). Distribution: Europe, Maghreb and western Asia.
Sorbus (Micromeles)
  • now genus Micromeles, a group of east Asian species with narrow leaves; sometimes previously included in subgenus Aria. Distribution: temperate and tropical east Asia.
Sorbus (Cormus)
  • now genus Cormus, with compound leaves similar to subgenus Sorbus, but with distinct fused carpels in the fruit; just one species, Cormus domestica (true service tree). Distribution: North Africa, warm-temperate Europe, western Asia. Used to flavour some apple wines, see Apfelwein.
Sorbus (Torminaria)
  • now genus Torminalis, with rather maple-like lobed leaves with pointed lobes; fruit carpels not fused; just one species (wild service tree). Distribution: warm-temperate Europe, south to the mountains of North Africa and east to the Caucasus and Lebanon ranges.
Sorbus (Chamaemespilus)
  • now genus Chamaemespilus, monotypic, with a single shrubby species, false medlar. Has simple, glabrous leaves and pink flowers with erect sepals and petals. Distribution: mountains of southern Europe.

Intergeneric hybrid genera

Uses

Ornamental trees

Sorbus species are cultivated as ornamental trees for parks and gardens and as avenue trees, and have given rise to several cultivars. The following, of mixed or uncertain parentage, have gained the Royal Horticultural Society's Award of Garden Merit:[6]

  • 'Eastern Promise'[7] (purple autumn colour, pink berries)
  • 'Leonard Messel' named for Leonard Messel of Nymans in Sussex.[8] (small tree to 4m, pink berries)
  • 'Wisley Gold' [9] (yellow berries)
  • Red rowan
    Red rowan
  • Rowan in the garden of Eastern Siberia
    Rowan in the garden of Eastern Siberia
  • New leaf from one Sorbus opens up.
    New leaf from one Sorbus opens up.

References

  1. ^ Robertson, K. R., J. B. Phipps, J. R. Rohrer, and P. G. Smith. 1991. A Synopsis of Genera in Maloideae (Rosaceae). Systematic Botany 16: 376–394.
  2. ^ McAllister, H. 2005. The Genus Sorbus: Mountain Ash and Other Rowans. Richmond, Surrey, UK: Royal Botanic Gardens, Kew.
  3. ^ Potter, D., T. Eriksson, R. C. Evans, S.-H. Oh, J. E. E. Smedmark, D.R. Morgan, M. S. Kerr, and C. S. Campbell. (2007). Phylogeny and classification of Rosaceae. Plant Systematics and Evolution. 266(1–2): 5–43.
  4. ^ Campbell C. S., R. C. Evans, D. R. Morgan, T. A. Dickinson, and M. P. Arsenault. 2007. Phylogeny of subtribe Pyrinae (formerly the Maloideae, Rosaceae): Limited resolution of a complex evolutionary history. Pl. Syst. Evol. 266: 119–145.
  5. ^ Rushforth, Keith (2018). The Whitebeam problem, and a solution. Phytologia 100(4): 222-247. 21 December 2018.
  6. ^ "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 98. Retrieved 12 November 2018.
  7. ^ "RHS Plantfinder - Sorbus 'Eastern Promise'". Retrieved 12 November 2018.
  8. ^ "RHS Plantfinder - Sorbus 'Leonard Messel'". Retrieved 12 November 2018.
  9. ^ "RHS Plantfinder - Sorbus 'Wisley Gold'". Retrieved 12 November 2018.

Further reading

Wikimedia Commons has media related to Sorbus.
  • Price, D.T. 2007. One-way introgressive hybridisation between Sorbus aria and S. torminalis (Rosaceae) in southern Britain. Watsonia. 26: 419–431.

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