Some key terms and features to look for when identifying ferns Pinnae (singular: pinna): Stem scales: thin, papery the first level of division scales attached to the stem. on a fern frond. These may be on the stipe Pinnule: the second level only or may extend up the of division on a fern frond. rachis. They are often rusty Pinnulet: the third level in colour. of division on a fern frond. Rachis: the term for the frond stem above where the leafy part of Sori (singular: sorus): the the frond begins. term for groups of sporangia. Sporangia (singular: Stipe: the term for the sporangium): individual frond stem below where spore-producing cases, often the leafy part of the found on the undersides of fronds. frond begins. Rhizome: the stem of a fern which either grows Indusia (singular: indusium): underground or at the a membranous layer that covers soil’s surface. They can the sori while the spores are be upright or grow maturing. This layer will often horizontally as a shed when spores are mature ‘creeping’ rhizome. and ready to release. Rhizome We are Plantlife For 30 years, Plantlife has had a single ideal – to save and celebrate wild flowers, plants and fungi. They are the life support for all our wildlife HRH The Prince Of Wales is our Patron and their colour and character light up our Plantlife landscapes. But without our help, this priceless Brewery House, 36 Milford Street, Salisbury, Wiltshire SP1 2AP natural heritage is in danger of being lost. 01722 342730 This guide to Ferns of Atlantic woodland was [email protected] created as part of the Building Resilience in South West Woodlands partnership project. www.plantlife.org.uk Plantlife is a charitable company limited by guarantee, Where wild flowers lead... company no.3166339. Registered in England and Wales, charity no.1059559. Registered in Scotland, charity no. SCO38951. Wildlife follows ©Plantlife, June 2020 ISBN: 978-1-913283-01-8 Photographs ©Roger Golding, Dr Alison Smith and Rachel Jones Designed and illustrated by evansgraphic.co.uk Ferns of Atlantic Printed by Blackmore, Shaftesbury, Dorset woodland This guide covers 14 of the common fern species Undivided Ferns with undivided fronds you are most likely to encounter in Atlantic Identifying ferns woodland (or temperate rainforest) habitat, The leafy part of a fern Hart’s-tongue fern Asplenium scolopendrium as well as two of the rarer species which are and its stem is known indicators of very healthy Atlantic woodland. For as a frond. Evergreen fronds glossy, narrow and strap-like, with a information on the 60 or so species of UK fern, we The frond may be entire heart-shaped base and pointed tip. Often becoming have suggested guides below. (as one leaf) or it may Pinnate: divided once undulate (wavy) at edge. Medium-sized fern with fronds be divided into smaller to around 60cm. What are ferns? segments called pinnae. Plants dark green and larger in shady conditions, pale green-yellow and stunted when exposed. Ferns appeared early in evolutionary history and have To begin with, it is useful Sori arranged in horizontal lines either side of the stem a primitive method of reproduction involving producing to look at the number of on frond underside. Early in the year these lines appear spores. They were among the first plants to develop a times the frond is divided Bipinnate: divided twice pale but later turn rusty brown. vascular system, including roots, xylem and phloem from the main stem. The name scolopendrium, from the Latin for centipede, is vessels, to transport water and nutrients. This large Ferns in this guide are due to the appearance of the underside where the linear evolutionary step forward from their predecessors grouped into those with sori look like the many legs of a centipede. This species the bryophytes (mosses and liverworts), which lack a fronds that are undivided, only ever grows where lime is found in the soil. vascular system and absorb water through their surface, pinnate (divided once), enabled them to grow much larger. Ferns have two bipinnate (divided twice) distinct parts to their life-cycle known as alternation of Tripinnate: divided and tripinnate (divided three times generations. The large, familiar plant we call a fern is a three times). Sori in lines spore-producing sporophyte. When these spores land in a suitable place to grow, they form gametophytes – tiny green heart-shaped growths (or prothalli) Ferns with pinnate fronds (divided once from main stem) that produce sexual cells. When male cells fertilise female cells, another sporophyte begins to grow. Hard fern Blechnum spicant The way a fern grows is a useful identification What are Atlantic woodlands and feature. Many ferns have Common in acidic woodland why do ferns thrive there? a short vertical stem with Evergreen fronds dark green, long and narrow, tapering Atlantic woodlands are a type of ancient semi- all the fronds arising gradually at the base and tip. Divided once into finger- natural, broad-leaved woodland. Often dominated from a central point, like leaf segments (known as ‘pinnae’), resembling ribs Shuttlecock by oak woods, they also include a mix of other tree giving a ‘shuttlecock’ or a ladder. Rather glossy and rigid. Medium-sized fern species, such as birch, alder, ash and hazel. Upland growth form. Some grow with fronds to around 40cm. ‘Sterile’ fronds visible all year, and grow from a central ash woods and Atlantic hazel woods are some of as an open rosette, while Sterile frond the most important Atlantic woodland habitats. others have a creeping, point in a rather lax rosette. In summer, ‘fertile’ fronds horizontal rhizome with rise vertically from the centre. The pinnae are narrower Atlantic woodlands are found in western Ireland and from fronds appearing to arise and more widely spaced, and the backs are covered in the west coast of Scotland, through the Lake District and rusty-coloured sori. Wales to south-west England, where the climate is mild individually from the surface they are growing on. Open rosette This fern has a strong dislike of lime in the soil and is and wet with little seasonal change due to the Gulf Stream. therefore a very good indicator of acidic conditions. This wet and humid climate allows ferns to survive without The presence of two different types of frond on the needing to access moisture deep in the soil. As well as same plant in summer is highly characteristic. growing on the forest floor, here ferns are able to grow as Other terminology and ID epiphytes on trees, rotting stumps, rocks and banks. The features described in this Fertile frond rarer filmy ferns, which are only found in the far west of guide are explained in the Britain, have very thin, translucent leaves. Vulnerable to glossary on the back page. Polypody Polypodium species drying out, they can only survive in very wet places. Creeping rhizome Common growing as an epiphyte on trees, banks and walls in damp places Further information Evergreen fronds are not glossy and are broad at the base and middle, narrowing towards the tip. The lower Books Websites pinnae are often folded inwards towards the middle of Key to Common Ferns (2005), Merryweather, J., Field www.ebps.org.uk The British Pteridological Society the frond. Small to medium-sized ferns with fronds Studies Council. website provides a wide range of information about ferns 10-40cm long. Ferns, Clubmosses, Quillworts and Horsetails of Cornwall including identification, courses, publications and a Round sori can be found on the back of the frond and and the Isles of Scilly (2012), Murphy, R.J., Page, C.N., comprehensive glossary. vary from yellow to orange. Parslow, R.E. and Bennallick, I.J., Environmental Records http://data.nbn.org.uk The NBN Gateway hosts an There are three very similar species of polypody: Centre for Cornwall and the Isles of Scilly. up-to-date database of British fern distribution. common, western and southern but they are difficult to separate. All can be found in the south-west and can also Britain’s Ferns, Clubmosses, Spikemosses, Quillworts http://rogergolding.co.uk/ferns hybridise. The name polypodium comes from the Greek and Horsetails (2020), Merryweather, J., Princeton Many of the images in this guide are taken from Roger poly (many) and pous (foot) referring to University Press. Golding’s website ‘Ferns in Britain and Ireland; A guide the branching nature of the rhizome. to ferns, horsetails, clubmosses and quillworts’. Underside of frond FOLD 2 FOLD 1 FOLD 2 Ferns with bipinnate fronds (divided twice from main stem) Male-fern Dryopteris filix-mas Scaly male-fern Dryopteris affinis agg A large deciduous fern with fronds to 100cm or more in Common in acidic woodlands with high rainfall length. Frond is broadest in the middle and narrower at base and tip. A large deciduous or semi-evergreen fern with fronds Pinnules taper to a pointed tip and the pinnule edges to around 150cm. Frond is broadest in the middle and have rounded teeth. narrower at base and tip. Stem scales are more sparse than in the scaly male- Pinnules parallel-sided to tapering, with square to ferns, and do not extend all the way up the rachis. rounded tips. Teeth on margins prominent to absent. One of our most common ferns, it can be separated from Stem scales are dense and golden to rusty-coloured. scaly male-fern (right) by looking at the underside of the These extend all the way up the rachis (but note that frond where the pinnae join the main stem. This junction scales rub off and may be sparse later in the season).