Alnus cordata

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Alnus cordata
Italian Alder foliage and
immature male catkins
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fagales
Family: Betulaceae
Genus: Alnus
Subgenus: Alnus
Species: A. cordata
Binomial name
Alnus cordata
(Loisel.) Duby
  • Betula cordata Loisel.
  • Alnus rotundifolia Bertol.
  • Alnus neapolitana Savi
  • Alnus cordata Desf., invalid, no description nor basionym reference
  • Alnus cordifolia Ten.
  • Alnus obcordata C.A.Mey. ex Steud.
  • Alnus macrocarpa Req. ex Nyman
  • Alnus nervosus Dippel
Alnus cordata tree

Alnus cordata (Italian alder[2]) is a species of alder in the family Betulaceae, native to southern Italy (including Sardinia and Sicily).[3] It is also considered native in Albania and Corsica, and naturalized in Belgium, Spain, and the Azores.[1]

It is a medium-sized tree growing up to 25 m tall[4] (exceptionally to 28 m), with a trunk up to 70–100 cm diameter. The leaves are deciduous but with a very long season in leaf, from April to December in the Northern Hemisphere; they are alternate, cordate (heart-shaped), rich glossy green, 5–12 cm long, with a finely serrated margin.

Italian Alder mature female (seed) catkins

The slender cylindrical male catkins are pendulous, reddish and up to 10 cm long;[4] pollination is in early spring, before the leaves emerge. The female catkins are ovoid, when mature in autumn 2–3 cm long and 1.5–2 cm broad, dark green to brown, hard, woody, and superficially similar to some conifer cones. The small winged seeds disperse through the winter, leaving the old woody, blackish 'cones' on the tree for up to a year after.

Like other alders, it is able to fix nitrogen from the air. It thrives on much drier soils than most other alders, and grows rapidly even under very unfavourable circumstances, which renders it extremely valuable for landscape planting on difficult sites such as mining spoil heaps and heavily compacted urban sites. It is commonly grown as a windbreak.

Alnus cordata has gained The Royal Horticultural Society's Award of Garden Merit.[5]


The Italian Alder makes a medium to large bonsai, a quick grower it responds well to pruning with branches ramifying well and leaf size reducing quite rapidly.[6]


  1. ^ a b Kew World Checklist of Selected Plant Families
  2. ^ "BSBI List 2007". Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-02-25. Retrieved 2014-10-17. 
  3. ^ Altervista Flora Italiana, Alnus cordata (Loisel.) Loisel.
  4. ^ a b Rushforth, Keith (1986) [1980]. Bäume [Pocket Guide to Trees] (in German) (2nd ed.). Bern: Hallwag AG. p. 91. ISBN 3-444-70130-6. 
  5. ^ "Alnus cordata AGM". The Royal Horticultural Society. Retrieved 25 August 2012. 
  6. ^ D'Cruz, Mark. "Ma-Ke Bonsai Care Guide for Alnus cordata". Ma-Ke Bonsai. Retrieved 2011-07-05.