Pollia pigmentation pooh-poohed

Image: Vignolini et al.

Image: Vignolini et al.

Despite appear­ances – and often there­fore assump­tions – to the con­trary, the intense blue-colour of the fruit of Pollia con­dens­ata is not due to pigment(s). Instead, it is another example of so-called ‘struc­tural col­our’ (a phe­nomenon that is much bet­ter known – if still incom­pletely under­stood – in anim­als than in plants), as repor­ted by Silvia Vignolini et al. The phe­nomenon in Pollia fruit (appar­ently, known as the ‘bling berry’ in recog­ni­tion of the slang term refer­ring to flashy, osten­ta­tious or elab­or­ate jew­ellery and orna­men­ted accessor­ies car­ried or worn by cer­tain indi­vidu­als) is an ‘example of multilayer-based strong iri­des­cent col­or­a­tion’, which gives the fruit a ‘strik­ing pixelated or poin­til­list appear­ance’. Furthermore, ‘The bright blue col­or­a­tion of this fruit is more intense than that of any pre­vi­ously described bio­lo­gical mater­ial’ (!!). Although the authors men­tion Pointillism (a paint­ing tech­nique in which small, dis­tinct dots of pure col­our are applied in pat­terns to form an image), it sounds more like sur­real­ism to me. Such an intense blue but which isn’t chem­ical must be a little bit dis­ap­point­ing to those Agricultural Research Service sci­ent­ists who are keen to exploit plant antho­cy­an­ins – which give blue col­ours to many plant parts – as pesti­cides. Structural col­our, eh? Bling it on!

Nigel Chaffey. ORCID 0000-0002-4231-9082

Nigel is a botanist and full-time academic at Bath Spa University (Bath, near Bristol, UK). As News Editor for the Annals of Botany he contributes the monthly Plant Cuttings column to that august international botanical organ. His main goal is to inform (hopefully, in an educational, and entertaining way...) about plants and plant-people interactions.