Nootka Update

Chamaecyparis nootkatensis has been floating out there in journal-space under a variety of new names, including assignments to Cupressus, Xanthocyparis, and Callitropsis. A summary of the main 5 papers involved appears at this link.
http://www.oregonflora.org/ofn/OFNv13n1.pdf

While the species has some lovely clones and a particularly popular one 'Pendula', the largest horticultural significance of the name change is the effect on x Cupressocyparis, a name based on Chamaecyparis x Cupressus parentage only. If Nootka goes back to Cupressus, the so-called bigeneric Leyland is now an intrageneric cross for which the name Cupressus x leylandii would be applied. If it gets placed as Xanthocyparis, the name x Cuprocyparis is already processed.

So where do we go for now? The senior and most experienced taxonomist in the Cupressaceae is unquestionably Dr. Robert Adams of Baylor with over 3 decades of work on the species. In his latest paper from February 2007...
http://www.juniperus.org/AdamsPapersPDFFiles/196-2007JEORXanthocyparisOils19-30-33.pdf...
he continues with the Xanthocyparis nootkatensis name. In his analysis, X. nootkatensis and X. vietnamensis both cluster apart from the Old World and New World Cupressus species.

A formal nomenclatural proposal to conserve Xanthocyparis over the very vague genus Callitropsis (which cannot be tied to another resembling the Nootka Cypress in my opinion) was made and has now been accepted. Some of Callitropsis thinking consider some species such as C. funebris to be a Chamaecyparis and not up for division between the other generic names.

Even persons in the Callitropsis camp vary in their opinions. Little considers the New World cypresses (ie. bakeri, arizonica, macrocarpa) to be part of Callitropsis but the Old World species (ie. funebris, sempervirens, torulosa) to remain with Cupressus.

On the other hand, if one wants to go with the Cupressus assignment, you have the USDA, calflora.org, and the prestigious Jepson Flora of Berkeley on your side.

The website http://www.cupressus.net/Masters.html is another good reference for information on the Cupressus Conservation Project and a list of good books.