Athrotaxis (Tasmanian cedar) description

Foliage and cones on an ornamental specimen of Athrotaxis × laxifolia, Pinetum Blijdenstein, Netherlands [C. J. Earle, 2010.06.11].

Seed cone of Athrotaxis × laxifolia [M. Frankis, 2003].

Distribution of Athrotaxis × laxifolia (Brown et al. 1983). You can also create a highly detailed map, and access specimen data, using the "search" function at the Australia Virtual Herbarium.

A. cupressoides, old tree by a tarn on the Shelf Tarns track, Mt. Field National Park [C. J. Earle, 2015.02.27].

A. cupressoides about 5 m tall, in alpine heath on the Shelf Tarns track, Mt. Field National Park [C. J. Earle, 2015.02.27].

A. selaginoides, seed cone approaching maturity, and an older pollen cone [C. J. Earle, 2015.03.01].

A. selaginoides seed cone section, showing developing seeds [C. J. Earle, 2015.03.01].

Uncommonly large trees of A. selaginoides [C. J. Earle, 2015.03.02].

Athrotaxis

D.Don (1838)

Common names

Tasmanian cedar.

Taxonomic notes

A genus of two species:

There is also one described fertile nothospecies, Athrotaxis × laxifolia Hook. (syn. A. × doniana Henk. & Hochst.; Type Specimen). Genetic analysis has found that this hybrid arises spontaneously and only occurs at sites where both parent species occur; the great majority of hybrid plants are F1 crosses or backcrosses, so the hybrid is effectively not self-reproducing despite being interfertile. There is no evidence that reproductive isolation has occurred between the hybrid and parent species, nor that hybridization is driving further isolation from the parent species. This leads to an inference that "Athrotaxis hybrid swarms are on a trajectory of decline and will eventually be reabsorbed by the parental species" (Worth et al. 2016). The same analysis found that A. cupressoides and A. selaginoides have highly dissimilar genetic makeups and "are likely the most divergent congeneric conifers known".

Description

Monoecious evergreen trees to 30 m tall, with a conical crown that usually becomes irregular with age. Bark reddish-brown, first smooth, flaky, later peeling off in thin, long strips. Twigs spreading, thick, ultimate twigs deciduous. Buds inconspicuous. Leaves scale-like, decurrent, imbricate, helically inserted, 5-ranked, uniform in shape and size. Pollen cones solitary at base of shoot, each with 10-15 helically arranged triangular microsporophylls; pollen globose, without a papilla. Seed cones terminal, solitary, woody, globose, maturing in one year, with up to 30 helically arranged scales. Seeds 3-6 per scale, oblong, thin, with 2 narrow even wings. Cotyledons 2 (Silba 1986, Farjon 2010).

There is really not much risk of mistaking Athrotaxis for anything else; the cones and foliage of each species are pretty much unique among conifers, though the seed cones and foliage of A. selaginoides and A. × laxifolia do bear a slight resemblance to those of Cryptomeria and Taiwania, two other conifer genera formerly assigned to the Taxodiaceae.

A. cupressoides has leaves so closely appressed and imbricate that the twigs resemble green dowels, hence the common name pencil pine. A. selaginoides has much larger leaves (7-18 × 3-4 mm), spreading distally from the twig. A. × laxifolia, has an intermediate appearance: leaves 4-12 × 2-3 mm, mostly connate but with a free tip (Farjon 2010 and my observations in habitat, 2015). See Worth et al. for photos comparing foliage of the three taxa.

Distribution and Ecology

The montane and subalpine portions of the temperate rain forests of Tasmania. Both taxa occasionally occur in open subalpine bogs and on rocky outcrops, and in those settings may adopt a krummholz growth form. Open subalpine areas are also the most common place to find A. × laxifolia, which occurs at elevations of 900 to 1200 m (ANBG [no date]).

The IUCN has classified A. × laxifolia as "Endangered", but this conclusion should probably be re-evaluated now that its status is known to be solely dependent upon the status and overlapping distribution of the parent species, both of which are assessed as "Vulnerable".

Remarkable Specimens

The largest and tallest trees are specimens of A. selaginoides. Comparable maximum ages are achieved by both species. Ogden (1985) cites, without reference to evidence, a claim of over 1,000 years for A. cupressoides; but he provides evidence in the form of a continuous tree-ring record of 777 years for A. selaginoides.

Ethnobotany

Neither species has been subject to much commercial use, likely due to limited accessibility and slow growth rates; they do see limited use for craftwood, though. Waldheim, a historically significant lodge at Cradle Mountain National Park, was built of A. selaginoides. Athrotaxis may have been used by aboriginal Tasmanians, but I can find no record of it.

Both species have been useful in dendrochronological research. A recent but brief review was presented by Allen et al. (2011), as part of an interesting dendroclimatic study. Norton & Palmer (1992) provide a general review; see the two species for particulars.

Observations

Both species can be readily seen at the principal National Parks within their range, of which the most accessible and probably the most remarkable is Cradle Mountain National Park. The trails behind Waldheim provide access to some of the finest surviving large, old specimens of A. selaginoides, while the hike up Cradle Mountain will show you alpine settings of A. cupressoides; in the same area i have seen A. × laxifolia along the track between Dove Lake and Weindorfer's Pillar. All taxa also occur at Mount Field National Park, where the Shelf Tarns walk is one of the best places to see very old specimens of A. cupressoides, as well as several areas with A. × laxifolia.

Remarks

The genus name is from the Greek, and means "crowded arrangement." The type description does not indicate what is crowded, but in both species, the twigs are completely sheathed in leaves. The epithet laxifolia refers to the wider spacing of the leaves, compared to other Athrotaxis species, which makes the twigs easily bendable.

Citations

Allen, K. J., J. Ogden, B. M. Buckley, E. R. Cook, and P. J. Baker. 2011. The potential to reconstruct broadscale climate indices associated with southeast Australian droughts from Athrotaxis species, Tasmania. Climate Dynamics, DOI 10.1007/s00382-011-1011-7.

[ANBG] Australian National Botanic Gardens. [no date]. Australian Conifers. http://www.anbg.gov.au/anbg/conifers/, accessed 2002.11.09, now defunct.

Donn, David. 1838. Annals of Natural History 1:234. Available: Biodiversity Heritage Library, accessed 2026.01.27.

Brown, M. J., J. B. Kirkpatrick and A. Moscal. 1983. An atlas of Tasmania's endemic flora. Hobart: Tasmania Conservation Trust. ISBN 0-9599816-8-3.

Worth, James R. P. , Matthew J. Larcombe, Shota Sakaguchi, James R. Marthick, David M. J. S. Bowman, Motomi Ito, and Gregory J. Jordan. 2016. Transient hybridization, not homoploid hybrid speciation, between ancient and deeply divergent conifers." American Journal of Botany 103(2):246-259.