Gold medal oak

Royal Botanic Gardens Melbourne, Victoria, 2020

Last week I was dissing the willow oak (Quercus phellos), blaming its lack of appeal on some rather plain (willow-like) leaves. This week's oak also has rather plainly cut leaves, without any scalloping or much serration at the edges, but it makes up for this in texture and 'secret' colour.

Texture first. The leaves above might look soft, like those of a coprosma, but the golden oak* (Quercus alnifolia) is one of those oaks with coarse, papery leaves. Not quite as 'dry' as the holm (Quercus ilex) or cork (Quercus suber) oaks, and some of the dryland oaks of California and Mexico, but the leaves wouldn't be out of place in an Australian heathland, where grevilleas and other protea-family relatives have similarly rugged leaves. We call them sclerophyllous.

Geoff Bogle's arboretum, Hoddles Creek, Victoria, 2020

The homeland of the golden oak is Cyprus, where it is one of three native species and the only one to not grow naturally outside the island (endemic to Cyprus, as we would say in biology). The other two are the Aleppo oak (Quercus infectoria subspecies veneris) and Kermes oak (Quercus coccifera subspecies calliprinos; the oak we plant as the Gallipoli oak).

Despite the extensive loss of forest in Cyprus, golden oak is still common, but only on Troodos Massif, where it is a particularly important component of rocky hillsides. It coppices easily and recovers quickly from fire.

When discovered in the eighteenth century, the tree was thought to be a kind of alder (Alnus) but with a distinctive feature that is celebrated in its common name - leaves with a golden undersurface. From above they are typically oak-green but underneath, as was observed in 1754, they are yellow when young, green-orange at their peak then brown in older leaves. The colour comes from a dense covering of felty hairs. 

Birregurra, Victoria, 2021

Geoff Bogle's arboretum, Hoddles Creek, Victoria, 2020

Birregurra, Victoria, 2021

Royal Botanic Gardens Melbourne (noting leaves with more prominently serrated edges), 2020

In 2005, a new variety of golden oak was named, Quercus alnifolia variety argentea. 'Argentea' means silvery, referring to the apparently distinctive colour on the undersurface of leaves in some trees. Given the variation in colour across its range in Cyprus and in cultivation, this varietal name is probably unnecessary.

The acorn cups are scaly like those of the Turkey oak but it's those parchment-like leaves with a golden underbelly that I like.

Geoff Bogle's arboretum, Hoddles Creek, Victoria, 2020

*As a few readers reminded me, the common name golden oak is also applied to a cultivar of English oak, Quercus robur 'Concordia'. The leaves on this tree are softer, yellow on both sides and shaped like a typical English oak leaf.