Hickel's fir; oyamel, pinabete [Mexican Spanish] (Farjon 2010).
Syn: A. religiosa (Kunth) Schlechtendahl et Chamisso subsp. hickelii (Flous et Gaussen) K. Strandby, K.I. Christensen, et M. Sørensen 2009.
There are two varieties, the type and A. hickelii Flous et Gaussen var. oaxacana (Martinez) Farjon et Silba 1990 (syn.: Abies oaxacana Martinez 1948; Abies hickelii Flous et Gaussen var. macrocarpa Martinez 1942.
Aguirre-Planter et al. (2000) studied genetic variability in the southern Mexican firs, Abies flinckii, A. guatemalensis, A. hickelii, and A. religiosa, and found that they all have low genetic diversity within populations, suggesting that they have each experienced genetic bottlenecks during their retreat to their current interglacial refugia (a biogeographic situation which also puts them at extreme risk from global warming). They also show high diversity between populations, supporting their treatment as separate taxa (although A. flinckii is here treated as a synonym of A. guatemalensis). Strandby et al. (2009), considering only a group of morphometric characters, further concluded that there are minimal differences between A. hickelii, A. guatemalensis, and A. religiosa, and designated them all as subspecies of A. religiosa. It seems more likely, though, that their analysis simply did not assess a sufficiently broad range of characters.
Trees to 30 m tall and 130 cm dbh, usually with a single, straight, round trunk, often clear for a good part of the tree's height; crown narrowly conical, less regular in old trees. Bark of at first smooth, gray, thickening with age and breaking up into quadrangular plates. Branches spreading horizontally, then ascending. Branchlets slender, purple- or red-brown, grooved, glabrous or slightly pubescent, with small, ovate or round leaf scars. Foliar buds ovoid, 5 x 4 mm, resinous; bud scales triangular, brown, persisting several years. Leaves on sun foliage angled forward; on shade foliage spirally arranged but appearing 2-ranked, diverging at nearly right angles to shoot, of about equal length; 18-35 × 1-1.8 mm, twisted or curved at base, shiny light green above, glaucous below; apex emarginate (sometimes obtuse). Stomata in two bands separated by a midrib below, none or a few near apex above. Pollen cones lateral, short, yellow with red microsporophylls. Seed cones lateral, erect, short pedunculate, oblong-cylindrical, with obtuse apex, 6-8 × 2.5-3.5 cm, purple ripening dark brown; rachis persistent, dark brown. Seed scales cuneate, 14 × 19 mm (at mid-cone); smooth, variably hairy; outer margin rounded, entire. Bracts 2 cm long, exserted. Seeds 6-7 mm long, light brown, with a light brown 10 x 8 mm wing (Farjon 2010).
The type and var. oaxacana are distinguished by the size of the seed cones; 6-8 × 2.5-3.5 cm in the type, and 9-12 × 5 cm in var. oaxacana (Farjon 2010).
S Mexico: Guererro, Oaxaca, and Chiapas at 2500-3000 m elevation. Climate cool, oceanic, winter-wet. Soils volcanic. Occasionally in pure stands (at the highest elevations), but usually in mixed stands; associates include Pinus montezumae, P. pseudostrobus, P. ayacahuite, Cupressus lusitanica and Quercus spp., above a shrub layer that may include Vaccinium spp., Andromeda spp., Ribes spp., and Fuchsia spp. (Farjon 2010). Hardy to Zone 8 (cold hardiness limit between -12.1°C and -6.7°C) (Bannister and Neuner 2001).
Habitat and distribution are the same for the type and var. oaxacana, except that var. oaxacana has not been described from Chiapas (Farjon 2010).
This species is listed as endangered in Mexico under NOM-ECOL-059-94.
One study performed in Oaxaca (Naylor 1971) found generally unsatisfactory results: all sampled trees were young, complacent, and could not be crossdated. This finding was attributed to an insufficiently seasonal climate. Further work can be located at the Bibliography of Dendrochronology.
In habitat, this rare species is seldom and then incidentally harvested for timber. It is rare in cultivation, largely limited to botanical gardens in areas with a warm-temperate climate.
The epithet commemorates the French botanist R. Hickel.
Aguirre-Planter, Erika, Glenn R. Furnier, and Luis E. Eguiarte. 2000. Low levels of genetic variation within and high levels of genetic differentiation among populations of species of Abies from southern Mexico and Guatemala. American Journal of Botany 87:362-371. Available: http://www.amjbot.org/cgi/content/abstract/87/3/362, accessed 2009.04.15.
Flous and Gaussen. 1932. Trav. Lab. Forest. Toulouse T. I (1, 17): 1.
Naylor, T.H. 1971. Dendrochronology in Oaxaca, Mexico: a preliminary study. Tree-Ring Bulletin 31:25-29. Available: www.treeringsociety.org/TRBTRR/TRBvol31_25-29.pdf, accessed 2006.06.14.
Strandby, U., K.I. Christensen, and M. Sørensen. 2009. A morphometric study of the Abies religiosa–hickelii–guatemalensis complex (Pinaceae) in Guatemala and Mexico. Plant Systematics and Evolution 280:59-76.
Farjon (1990) provides a detailed account, with illustrations.
Last Modified 2013-12-22