Cupressus austrotibetica Silba

A number of new species of Cupressus have been described in the various publications by John Silba (for example, Silba 1981a, 1983, 1998). While these species have not received wide recognition within the taxonomic community (see, for example, Farjon 2005c), seed has been distributed under some Silba names, including C. austrotibetica and C. tonkinensis. Some of the resultant plants do appear distinctive, causing confusion as to their identity, particularly in the absence of a horticultural authority on the subject. It must be pointed out that the seeds distributed by Silba (and his confederates in source countries) cannot be conclusively linked to particular Silba names; they may only be linked by a common source locality. Cultivated plants bearing these names should therefore be regarded with great suspicion. A recent molecular study suggests that there is considerable variation in eastern Asian Cupressus, variation that is not encompassed fully by modern taxonomic treatments (Rushforth et al. 2003).