Abies homolepis

Scientific name: Abies homolepis  Siebold et Zuccarini  1842

Synonyms: Abies brachyphylla Maxim., Abies finhonnoskiana R.Neumann ex Parl., Abies harryana W.R.McNab, Abies tschonoskiana Regel, Picea brachyphylla (Maxim.) Gordon, Picea homolepis (Siebold & Zucc.) Carrière, Picea pinnosa Mast., Picea tschonofskiana (Regel) Mast., Pinus homolepis (Siebold & Zucc.) Antoine

Common names: Nikko fir, Urajiro-momi(Japanese)

Description

Tree to 30(-40) m tall, with trunk to 1(-1.5) m in diameter. Bark gray, becoming browner and flaky with age. Branchlets hairless and shiny, deeply grooved between the leaf bases. Buds 3-5 mm long, moderately to heavily resinous. Needles arranged to the sides of the twigs in several rows, 1-2.5(-3.5) cm long, shiny dark green above, the tips sharply forked on young trees, simply notched or blunt on older ones. Individual needles flat in cross section and with a large resin canal in the center of each side of the leaf, without stomates above and with 11-13 lines of stomates in each white stomatal band beneath. Pollen cones 10-20 mm long, yellowish brown. Seed cones (7-)9-12 cm long, 3-4 cm across, dark purple when young, ripening purplish brown. Bracts about half as long as the seed scales and hidden by them (hence the scientific name “uniform scales”, in contrast to Abies firma). Persistent cone axis narrowly cylindrical. Seed body 6-9 mm long, the wing about as long. Cotyledons four (or five).

Central Honshū, Kii Peninsula, and Shikoku (Japan). Occasionally forming pure stands but more often mixed with numerous other montane forest conifers and fewer hardwoods in the elevational belt between Abies firma and Abies veitchii; (700-)1,000-1,800(-2,200) m. The climate is cool and humid.

Conservation Status

Red List Category & Criteria: Near Threatened

The fragmentation of the outlying populations with consequent reduction in population size and range in the recent past gives rise to the possibility of Abies homolepis becoming threatened in the future, especially if Japanese deer numbers continue to increase. Therefore the use of the Near Threatened category is justified. Near the tree limit it forms either pure stands, or mixtures with Abies veitchii and/or Larix kaempferi, but at lower elevations it occurs in the mixed coniferous deciduous forests, with e.g. Fagus crenata, Quercus crispula, Betula grossa, Tsuga diversifolia, Thuja standishii, Pinus densiflora. Abies firma replaces Abies homolepis below 1,100 m. It is fairly widely planted as an ornamental tree in Japan as well as in Europe, where it appears to be one of the least demanding species in the genus. A few cultivars are known in Japan as well as in Europe (independently derived), mostly being dwarfed forms suitable for Japanese gardens or rockeries. There is no special protection system for this species. However, most localities are now at least protected from logging.

References

• Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
• Eckenwalder, J.E. (2009) Conifers of the World: The Complete Reference. Timber Press, Portland.
• IUCN Red List of Threatened Species, International Union for Conservation of Nature and Natural Resources. Cambridge, UK /Gland, Switzerland

Copyright © Aljos Farjon, James E. Eckenwalder, IUCN, Conifers Garden. All rights reserved.