Corylus colchica Albov

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Credits

Owen Johnson & Richard Moore (2023)

Recommended citation
Johnson, O. & Moore, R. (2023), 'Corylus colchica' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/corylus/corylus-colchica/). Accessed 2024-04-15.

Genus

Common Names

  • Georgian Hazel

Glossary

IUCN
World Conservation Union (formerly the International Union for the Conservation of Nature).
Vulnerable
IUCN Red List conservation category: ‘facing a high risk of extinction in the wild’.
endemic
(of a plant or an animal) Found in a native state only within a defined region or country.
included
(botanical) Contained within another part or organ.

Credits

Owen Johnson & Richard Moore (2023)

Recommended citation
Johnson, O. & Moore, R. (2023), 'Corylus colchica' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/corylus/corylus-colchica/). Accessed 2024-04-15.

Shrub, often only 1 m tall in the wild. Twigs grey, with dense silky hairs in their first year. Leaves small (50–70 × 35–45 mm), ovate, sometimes cordate at the base and with abruptly acuminate tips, doubly toothed, sparsely hairy above and densely so under the veins; petiole hairy, c. 1 cm long. Nuts small (c. 11–13 mm long), carried singly or in groups; husk wrapping the nut and constricted beyond it into a short beak, which may be so deeply lobed that the top of the nut remains unwrapped. Flowering April (in situ); nuts ripening in September. (Bush 1939; Cherepanov 1995; Grossheim 1945; Sokolov & Svjazeva 1977).

Distribution  Georgia

Habitat High, limestone mountains; forming thickets towards the tree-line.

USDA Hardiness Zone 5

RHS Hardiness Rating H6

Conservation status Vulnerable (VU)

Corylus colchica is one of the least understood hazel species, and the only one to have been assessed as Vulnerable by the IUCN; it is believed to be endemic to the Bzipi, Arabika, Kodori and Egrisi mountain ranges in Georgia, though a few authorities suggest that the wild distribution may extend east into Armenia. In all these areas it is threatened by grazing and forest clearance and there are only some fifteen to twenty small, severely fragmented sub-populations left; there may be little or no monitoring or protection of the remaining stands (Shaw et al. 2014). It is cultivated in the National Botanical Garden of Georgia (iNaturalist 2023), but this is one of only two known ex-situ collections (Beech, Shaw & Jones 2015).

Threatened plants should perhaps be the best studied ones, but there are various reasons why they are often the least studied. Some botanists treat C. colchica as synonymous with C. avellana, or even with the tree-sized C. colurna (Nasir 1976). C. colchica has not apparently been included in any major phylogenetic studies of the genus (Yang et al. 2018); this is particularly unfortunate since its long husks and its apparent wild status provide one of the likeliest origins for the long-husk genes within today’s population of European fruiting hazels. (See C. maxima for a further discussion of this subject.)

There is a thriving hazelnut industry in Georgia, confined to much lower elevations than the wild stands of C. colchica (Mirotadze 2005). Dr Nana Mirotadze assumes that C. colchica was one ancestor of at least some of the local fruiting clones, which include ‘Gulshishvela’, ‘Shveliskura’, ‘Khachapura’, ‘Anakliuri’, ‘Dedoplis Titi’, ‘Nemsa’ and ‘Saivanobo’ – the other ancestor being C. avellana (in its eastern but questionable var. pontica). The nuts of wild C. colchica are small, but it is of particular interest as a very hardy plant.