Plants & People Taxonomy & Evolution

Can’t Botanists agree on common names..?

A rose by any other name... would be incorrectly described.
Image of the brown seaweed Pelvetia canaliculata, also known as channel(l)(ed) wrack [from Wikipedia by Patrice78500]

I had the great pleasure recently to read – and appraise – the most excellent book Rocky Shores, by John Archer-Thompson and Julian Cremona.

The book contained lots of new material – for me at least! – but one of the most surprising things was its use of ‘channel wrack’ as the common name for Pelvetia canaliculata (a brown seaweed found towards the top of the shore, in Norway, Iceland, UK, Ireland, Atlantic coast of France, Spain and Portugal…). Although this version of the seaweed’s common name is used consistently throughout Rocky Shores, I’m more used to seeing it spelt as channelled wrack. This seems sensible since channelled, as an adjective, refers to the grooves – ‘channels’ – found on the fronds of this macroalga (“The fronds of the algae are curled longitudinally forming a channel”). Using ‘channel’ as a noun looks odd in this context *. However, suitably intrigued by this major difference in naming, I did some digging, and what I discovered was ‘interesting’…

Readily-available sources [i.e. items in Mr Cuttings’ marine biology library and others found on-line with minimal ‘Googling’] using channelled are: Fish & Fish’s A student’s guide to the seashore (3e; p. 64); CM Yonge’s The sea shore (plate III); Carola Dickinson’s British Seaweeds (p. 109); Ray Gibson et al’s Photographic guide to the sea & shore life of Britain and north-west Europe (p. 30); AC Campbell’s The Hamlyn guide to the seashore and shallow seas of Britain and Europe (p. 38); Heather Angel’s Seaweeds of the seashore (Fig. 2); The big seaweed search guide; The shore thing teachers’ pack []; the NBN Atlas; MarLin, Marine Information Network Information on the species and habitats around the coasts and sea of the British Isles; and The seaweed site – although here spelt chaneled, the American way.

In contrast, channel wrack is the name used in: John Barrett & CM Yonge’s Collins pocket guide to the sea shore (p. 226), both editions of Francis Bunker et al’s Seasearch guide to seaweeds of Britain and Ireland (1e, p. 173; 2e, p. 275); Sue Hiscock’s A field key to the British brown seaweeds (Phaeophyta) (Field Studies 5: 1-44, 1979); and the Field Studies Council’s seashore site.

Maybe wisely, no common name is given for this macroalga in the iconic textbook on rocky shore ecology, John Robert Lewis’ The ecology of rocky shores, nor in Emma Wells’ A Field Guide to the British Seaweeds As required for assistance in the classification of water bodies under the Water Framework Directive.

Although there appears to be a clear bias towards use of channel(l)ed, there is no universal consensus. So, perhaps the last word – for now..? – on this topic should go to the AlgaeBase site, which states that two of the English common names for Pelvetia canaliculata are channelled wrack AND [my emphasis…] channel wrack.

All of which contentious classificatory confusion is a good argument for why we should use the scientific names – either as well as or instead of – the common names of plants and plant-like organisms (and probably other taxa…)!

* Being a little bit mischievous, I like the name channel wrack because it allows me to tell my students that the seaweed is so-called because it is found on the sheltered shores of the Bristol Channel [it is found there (e.g. John Crothers, Field Studies 4: 369-389, 1976, but that’s not the reason for the seaweed’s name, well not as far as I know…]. And. if I wanted to assess the gullibility of my students I might also be tempted to suggest  that ‘chanel’ wrack – another spelling variant that I may have just made up… – is an allusion to the odour of a perfume product from a major name in the fragrance business, or the smell of ‘cocoa’, that emanates from the seaweed when crushed… But I wouldn’t do that, would I?