Many blue spruce trees in our area are suffering from a progressive decline. This is more than the usual combination cytospora canker & rhizospaera needlecast that tend to make most mature blue spruce look crappy. The current syndrome has been linked to phomopsis blight and affected trees show increasing branch die-back and in some cases trees go from a having a few dead branches to completely dead in a 3-4 years. Because of this alarming and pervasive issue, I’ve been asked to put together a list of alternative selections for blue spruce as part of my extension duties.
Whenever I put together one of these lists I always include my all-time favorite conifer; a graceful, elegant tree that is native to the Pacific Northwest but grows well in Michigan and fulfills a range functions in the landscape. Of course that tree is… well, that’s the problem. I’m not sure what to call it anymore. In Mr. Chance’s 6th period Botany class at Olympia High School 30-some years ago I learned it as Alaska yellow cedar, Chamaecyparis nootkatensis. Had to get the Latin spelling right to get full credit. When I moved to Michigan in 1999 I heard people talk about Alaska cypress or Nootka cypress. Took me a minute but I figured it out. At least I could take comfort in the scientific name. After all, as Mr. Chance taught us, we use scientific names to eliminate confusion; using Latin since it is ‘dead’ language and not subject to change.
About the same time I came to MSU a new conifer was discovered in Vietnam. The new tree, Vietnamese golden cypress, was originally described as Xanthocyparis vietnamensis. Moreover, this new species was closely related to nootkatensis, so both were added to the new genus. Subsequently it was argued that the genus Callitropsis was originally used for Xanthocyparis nootkatensis before it became Chamaecyparis. So, based on precedent Callitropsis was the proper genus for nootkatensis and vietnamesis. Got it? Well, as Lee Corso would say, Not so fast my friend… Here’s the rest of story from the font of all knowledge, Wikipedia:
‘In 2010, Mao et al. performed a more detailed molecular analysis and placed Nootka Cypress back to Cupressus. However, this is disputed, as the tree would compose a monophyletic subgenus. "The argument that it warrants treatment as a monotypic genus is not without merit, in which case the correct name is Callitropsis nootkatensis."’
Then the Wikipedia poster shows their true colors.
‘Although acceptance of the revised classification of this tree is widespread among botanists, inertia in the horticultural and forestry industries (both typically very slow to adopt the results of botanical research), mean the name Chamaecyparis nootkatensis is likely to continue being listed in many situations.’
So let me get this straight. Taxonomists have put the tree in four different genera within ten years and in one sentence current molecular analysis puts the tree in Cupressus (which the International Botanic Congress approved last year) but that’s disputed by other botanists – and WE’RE the idiots because we won’t jump on board?!