Cheers Tim, I think you're onto something there. Simpson and Thomson do note the purple bristles that are restricted to the margin only in my photo of a Mt Rakeahua plant but spread over the upper lamina in your Table Hill plant. Just looked at a specimen of B. bellidioides from Macraes, Central Otago and that has no purple/dark bristles. Sample size of one, but I'll keep an eye open next field season