New publication will help British and Irish botanists to record wildflowers.

Possible hybrid between Heath
Spotted-orchid & Northern Marsh-orchid.
Courtesy of J. Crellin
http://www.floralimages.co.uk/page.php?
taxon=dactylorhiza_x_formosa,1

BSBI is delighted to announce the publication of the Hybrid Flora of the British Isles by Clive Stace, Chris Preston & David Pearman.

As Professor Richard Abbott says in his Foreword “This remarkable book will be an essential reference for all British and Irish botanists who have an interest in hybrids. … No other book of its kind exists for other parts of the world and consequently this book will surely set the standard for future hybrid floras”.

Plant hybrids are numerous and constitute an important feature of our vegetation. Some are already well-known, such as the hybrid bluebells now frequent throughout much of Britain, but fewer people are aware that many of our oak trees and wild orchids are hybrids, or that some of our Japanese Knotweed - which causes landowners such nightmares - is actually a hybrid between Japanese and Giant Knotweeds.  

  

Hybrid between English & Sessile oaks?
Courtesy of J. Crellin
http://www.floralimages.co.uk/page.php?
taxon=quercus_x_rosacea,1

Chris Preston says “New hybrids between native and garden plants are arising all the time” but all too often hybrids have been neglected by botanists as they are considered difficult and time-consuming. The Hybrid Flora of the British Isles will be of huge value to BSBI botanists who record the distribution of plants growing in the wild across Britain and Ireland and share this information on interactive maps and in atlases. 

The data collected by BSBI members, once validated, feed into one of the largest biological databases in the world, used by policy-makers, conservationists and academia.

With this new reference work, hybrids can be identified more accurately, recorded more confidently and validated more easily, increasing the flow of reliable records to the BSBI database and deepening our knowledge and understanding of which plants grow where across Britain and Ireland.

Hybrid larch
Courtesy of J. Crellin
http://www.floralimages.co.uk/page.php?
taxon=larix_x_marschlinsii,1

The Hybrid Flora of the British Isles will be used by botanists seeking to identify hybrids in the field, by evolutionary biologists investigating the significance of plant hybridisation or its contribution to the spread of introduced plants, by conservation biologists seeking to protect our biodiversity and by all those teaching about these topics. 

It both summarises existing knowledge and highlights some significant gaps in that knowledge which need to be filled by future research.

Hybrid between Wood Avens & Water Avens
Courtesy of J. Crellin
http://www.floralimages.co.uk/page.php?
taxon=geum_x_intermedium,1

Stace, Preston and Pearman offer detailed accounts of 909 hybrids reliably recorded in the wild in these islands: some are hybrids between native species, which have spread beyond the areas where their parents coexist, but there are also many hybrids which have escaped from gardens to become established in the wild. 

Hybridisation between species is particularly significant as it represents a major evolutionary pathway in flowering plants; frequently it alters the characteristics of both native and alien taxa and it generates new species.

BSBI data on distribution of hybrids growing in the wild provide a valuable resource for researchers, making the British and Irish hybrid flora one of the most closely studied in the world and offering the eminent authors of the Hybrid Flora of the British Isles an ideal opportunity to look in depth at the occurrence of hybrids in wild vegetation.

Clive Stace in the Herbarium, Univ. Leicester
Image: L. Marsh

Clive Stace is Emeritus Professor of Plant Taxonomy at the University of Leicester and the author of the New Flora of the British Isles, now in its third edition and widely acknowledged as the most authoritative work of its kind, designed to enable botanists to identify any plant found in the wild in Britain or Ireland.

Co-authors Dr Chris Preston and David Pearman are also co-authors (with Dr Trevor Dines) of the New Atlas of the British & Irish Flora, 2002, which aimed to map all the plants growing in the wild in Britain and Ireland. Both Clive and David have served a term as BSBI President, while Chris is a stalwart of BSBI Publications Committee and sits on the Editorial Board of New Journal of Botany. 

New Atlas authors reunited, Kew, 2014:
Pearman, Preston & Dines (r-l)
Image: L. Marsh

The accounts of 909 hybrids in the Hybrid Flora of the British Isles include notes on identification, habitats and distribution, chromosome number, information on fertility/sterility and capacity for vegetative reproduction. 

Completely novel maps, based on the plant records collected by BSBI members, illustrate where the commoner hybrids occur in relation to their parents. 

Summaries are given of any experimental and molecular studies and briefer notes are given on a further 156 hybrids, including some which are erroneously or doubtfully recorded and others which might potentially occur as escapes from cultivation. 

The Hybrid Flora of the British Isles is a BSBI publication and is now available from booksellers such as Summerfield Books and the NHBS.