Non-Vascular Plants and Fungi Author(S): Humphries, C
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http://www.natsca.org Care and Conservation of Natural History Collections Title: Non-vascular plants and fungi Author(s): Humphries, C. J. & Huxley, R. Source: Humphries, C. J. & Huxley, R. (1999). Non-vascular plants and fungi. In: Carter, D. & Walker, A. (eds). (1999). Chapter 4: Care and Conservation of Natural History Collections. Oxford: Butterwoth Heinemann, pp. 81 - 91. URL: http://www.natsca.org/care-and-conservation The pages that follow are reproduced with permission from publishers, editors and all contributors from Carter, D. & Walker, A. K. (1999). Care and Conservation of Natural History Collections. Oxford: Butterworth Heinemann. While this text was accurate at the time of publishing (1999), current advice may differ. NatSCA are looking to provide more current guidance and offer these pages as reference materials to be considered alongside other sources. The following pages are the result of optical character recognition and may contain misinterpreted characters. If you do find errors, please email [email protected] citing the title of the document and page number; we will do our best to correct them. NatSCA supports open access publication as part of its mission is to promote and support natural science collections. NatSCA uses the Creative Commons Attribution License (CCAL) http://creativecommons.org/licenses/by/2.5/ for all works we publish. Under CCAL authors retain ownership of the copyright for their article, but authors allow anyone to download, reuse, reprint, modify, distribute, and/or copy articles in NatSCA publications, so long as the original authors and source are cited. 4 Non-vascular plants and fungi C. J. Humphries and R. Huxley Department of Botany, The Natural History Museum, Cromwell Road, London SW7 SBD. UK wildlife. Many species have commercial signif- Introduction icance, such as seaweeds utilized as fertilizers, This chapter describes the methods used to alginates for chemical extracts and others used conserve fungi (including lichens), red and as sources of food and medicine. brown algae, much of the green plant Glade, Care and conservation of specimens depends except for vascular plants, including photo- on many different aspects including collecting synthetic blue-green algae, and other micro- equipment, restoration, mounting, fixing, organismic `plants', green algae, charophytes, storing, documentation and different stages of bryophytes, including mosses, liverworts and the life cycle (e.g. spores, gametophytes, hornworts. For horse-tails, lycopods, ferns and sporophytes). Each group of organisms require flowering plants see Chapter 3 on vascular different methods of treatment from the plants. Organisms included as non-flowering moment the organisms are collected to the plants do not constitute a monophyletic group point when they are laid out in the herbarium but refer instead to almost any non-vascular or stored in the slide collection. The chapter is autotrophic organisms, saprophytes and organized so as to describe the individual parasites maintained within a herbarium. This groups and the methods applied to them. chapter describes a selection of techniques used in herbaria. These plants are stored in myriad ways including pressed dried specimens Fungi on flat sheets of paper, air-dried specimens in boxes or envelopes, freeze-dried specimens in Fungi are a diverse group of organisms which air-tight containers, fixed cells on slides and as are difficult to define (Ainsworth et al., 1973; three-dimensional, liquid preserved specimens. Alexopoulos et al., 1996). Mycologists have There is a burgeoning interest in these variously described fungi as eukaryotic, spore- organisms and an increasing need to maintain producing, achlorophyllous organisms with and conserve voucher specimens and authentic absorptive nutrition. They are usually filamen- material identified by specialists. Nonflowering tous, branched somatic structures with hyphae plants are increasing in importance, with typically surrounded by cell walls comprised of groups such as lichens and bryophytes being cellulose or chitin (Alexopoulos et al., 1996). used as pollution indicators, many water-borne Hawksworth (1991) estimates that there are taxa being seen as important indicators of 69,000 species of fungi world-wide. water quality and, conversely. various algae Collection and preservation of fungi require being toxic to fish and other specialist skills and are best undertaken by trained mycologists for successful results 81 82 Care and Conservation of Natural History Collections (Hawksworth, 1974). Fungi are variously polypores and resupinate fungi. For best classified but for the purposes of this book can results the cap is placed on to a glass sheet or be considered as four major groups: piece of white paper inside an air-tight vessel Chytridiomycota (water moulds, Allomyces, with a drop of water or a damp piece of cotton etc.), Zvgomycota (bread moulds, Rhizopus, wool. The specimen is placed hymenial side Mucor etc.), Ascomycota (sac fungi, yeast, down and left in a cool place from anything Penicillin in etc.) and Basidiomycota (mush- from two hours to overnight. Bridson and rooms, rusts, smuts etc.). Myxomycetes (slime Forman (1992) note that polypores and moulds) are not true fungi. They lack hyphae resupinate fungi often have extremely short and have an amoeboid stage as the principal sporulation periods and indeed spores of some part of the life cycle, but are generally associ- species have yet to be described. For these ated with fungal herbaria. Mature fruiting taxa, spore prints are extremely valuable. It is bodies (sporangia) do take on the appearance important to keep precise collecting numbers of fungi and are filled with a powdery spore so as not to mix up samples. Once collected mass (Alexopoulos et al., 1996). spore samples are air-dried and kept with the parent specimens. Collecting Preservation and storage Fleshy fungi (fruiting bodies of ascomycetes and basidiomycetes) are best collected into Because fungi deteriorate very rapidly it is flat-bottomed baskets (trugs) or open boxes so necessary that specimens are dried as quickly as to minimize damage during transport. as possible to retain their shape and colour. Different species should be kept separate from Small specimens can be preserved intact but one another in the field by wrapping them in very large specimens need to be dissected into thick, waxed paper or putting them inside open pieces to accelerate the drying process. pots. Only good specimens should be Specimens are dried in a warm room in a warm incorporated into the herbarium with as little stream of air around 40°C. Bridson and damage as possible and using as much of the Forman note that higher temperatures cook structure as is available, particularly the base the specimens whilst lower ones allow insect of the stipe and the volva in the case of fructi- larvae to hatch out and damage them. For fication of agaric taxa. small specimens air-drying in the sun is suffi- Fungi deteriorate very rapidly and undergo cient for preservation, but field-drying can be size changes during the drying out process. undertaken using a combination of a fan and a Therefore it is essential to provide overall field portable field stove or with light bulbs in a descriptions, including details of colour, drying box. Specimens to be dried can be shapes of gills, teeth and pores. Special arranged on to racks or suspended from lines. attention should be given to surface features, In the tropics and other areas of high humidity texture, odour and taste. However, it should be it is important to ensure that dried specimens pointed out that some fungi are deadly if eaten continue to be kept dry after preparation. They and therefore tasting is not recommended can be stored in zip-top polythene bags unless identity can be guaranteed. Colour containing silica gel or, ideally, stored in a glass photographs and water-colour paintings are of desiccator over calcium chloride. Rusts and great help for assisting later work in the parasitic fungi living on plants can be collected herbarium. Drawings of cross-sections of and dried with the host substrate in plant fruiting caps for mushrooms and toadstools presses, just as for vascular plants. helps to provide details of gill attachment. It was once believed that freeze-drying of fungi would be the panacea for the storage of Spores larger fungi but there are no advantages for The necessity of obtaining spore deposits for scientific investigation. It is now thought that larger fungi cannot be over-emphasized freeze-drying might be useful for the presen- (Bridson and Forman, 1992). Spores are useful tation of exhibition material but such speci- for diagnostics and descriptions of agarics, mens are fragile and easily broken. Non-vascular plants and fungi Lichens leather (James, 1958). It is important to collect some of the substrate to which the plant is A lichen is an association of a fungus with algae attached but to minimize the bulk it is neces- or cyanobacteria and the organisms are sary to take a tool-kit, a geological hammer, a interwoven to form a single thallus. The range of cold-steel chisels, a stout, sharp knife, `mycobiont' is the fungal portion of the thallus secateurs, a trowel, a hand lens and soft and the `photobiont' is the photosynthetic tissue-paper for wrapping the specimens in the component. Nearly half of the world's described field. fungi are ascomycetes and about half of these Lichens can be grouped mainly by habit into live in association with algae as lichens. Of the crustose, foliose and fruticose forms, although ascomycetous lichen-forming fungi the majority these distinctions flow imperceptibly into one are discomycetes. Of the discomycetes almost another and should in no way be interpreted as all are lecanoralean. Other groups of representing natural groups. lichen-forming fungi are loculoascomycetes. A much smaller number of pyrenomycetes and Crustose lichens basidiomycetes also form lichens (Alexopoulos et In crustose lichens the thallus spreads over the al., 1996), and it is the fungal component that substratum forming a distinctive coating or determines their systematics and nomenclature.