Alnus × elliptica Req.

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Credits

Tim Baxter & Hugh A. McAllister (2024)

Recommended citation
Baxter, T. & McAllister, H.A. (2024), 'Alnus × elliptica' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/alnus/alnus-x-elliptica/). Accessed 2024-04-15.

Genus

  • Alnus
  • A. cordata × A. glutinosa

Glossary

cordate
Heart-shaped (i.e. with two equal lobes at the base).
hybrid
Plant originating from the cross-fertilisation of genetically distinct individuals (e.g. two species or two subspecies).

Credits

Tim Baxter & Hugh A. McAllister (2024)

Recommended citation
Baxter, T. & McAllister, H.A. (2024), 'Alnus × elliptica' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/alnus/alnus-x-elliptica/). Accessed 2024-04-15.

A natural hybrid between Alnus glutinosa and A. cordata, intermediate between the parents. Leaves oval to sub-orbicular 3–8 × 2–7 cm, apex obtuse to slightly emarginate, base cordate to broadly cuneate, teeth serrulate-dentate, blade glossy dark green above, glabrous except for hairy domatia beneath. Male inflorescences 2–4 in terminal clusters, 20–40 × 6–8 mm in bud, at anthesis 70–100 mm long. Fruit borne below male catkins, 20–35 × 20 mm, ovate-elliptic. (Tutin et al. 1972).

Distribution  France Corsica, close to the mouth of the River Salenzara

USDA Hardiness Zone 5-7

RHS Hardiness Rating H6

Whilst clearly intermediate between the two parents, Alnus × elliptica is, perhaps, most similar to A. cordata in its glossy, leathery leaves, but in the hybrid these are much broader and sometimes slightly lobed, and usually lack the cordate base. There was once an example over 21 m tall on the bank of the lake at Kew, long since lost; it was of unknown origin and originally labelled ‘A. cordifolia var.’ until identified as A. × elliptica (Bean 1976). A pair growing at RBG Edinburgh under the accession number 19510146 were labelled ‘A. glutinosa hybrid’, perhaps suggesting a hybrid swarm arose in cultivation in the past. One of the Edinburgh trees was lost in a devastating storm on 3rd January 2012; in summer 2021 the other remains firmly rooted (T. Christian pers. comm. 2021). Other extant trees in the UK are growing at the Savill Garden, Windsor, at Wynkcoombe Hill, Sussex, and at Sheffield Botanic Garden (Tree Register 2008). It is otherwise rare in cultivation but would merit wider planting. See also A. glutinosa Hybrids.