A closer look at lichen Lobaria

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Following on from a randomised survey of all British lichens in the Natural History Museum’s collection (see previous blog), I completed my week there finding out more about one particular British lichen, Lobaria amplissima.   For all 109 specimens of the lichen, as well as recording the same information as in the previous survey, I was particularly looking for the presence or absence of cephalodia* and apothecia**.

Lobaria amplissima is a large, ‘leafy’ lichen, normally green but paler when dry.  It is sensitive to toxins making it a good indicator of ecosystem health.  It is found on Ash, Oak and Sycamore, often in old woodlands and predominantly to areas in the west of the UK  where the air is cleanest – North and West Scotland, Cumbria and Devon and Cornwall.

Combined with information in other local and national databases, the data recorded may make it possible to identify more precisely any changes in the geographical distribution of the species over time, and any correlation between environmental changes and the presence of nitrogen-fixing cephalodia and/or the sustainability of colonies.

*Cephalodia

Lobaria amplissima is relatively unusual in that as well as the symbiosis between a fungus and a green alga in the ‘leafy’ structure (thallus), a cyanobacterium is also involved.  The cyanobacteria form brown-black gall-like structures called cephalodia, which can be seen in the photo above as small black nodules.   The alga and cyanobacteria provide food to the fungus through photosynthesis and, in addition,  the lichen gets added nitrogen from the cyanobacteria in the cephalodia, which may be an advantage in nitrogen-deficient environments.

**Apothecia

In the photo above, the red-brown cup-shaped structures are apothecia, the fruiting bodies from which spores are released.  They mean the lichen is reproducing sexually, an indicator of the vitality of the organism.  Organisms which only reproduce asexually can be vulnerable to environmental changes since mutation is the only way new genetic combinations can appear.

A more recent specimen, showing neither apothecia nor cephalodia.

A more recent specimen, showing neither apothecia nor cephalodia.

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As well as the privilege of working with the lichens themselves, the label information made it a fascinating task. Was the collector aware of the impending cataclysm?

Thanks to Dr Holger Thus for the opportunity to work with this wonderful collection and delve a little deeper into these amazing organisms.

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A catalogue of earwig types

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Just before Christmas I completed a draft catalogue of the type specimens in Manchester Museum’s Dermaptera (earwig) collection.

The museum has about 11,000 Dermaptera including type material for 276 species.

There are 60 trays of earwigs  in 3 cabinets, where they are laid out by genus, and within genus by species.

This drawer shows the great variety between the species.

They show a fascinating variety.

The dried specimens are either pinned directly, or glued onto card which is on a pin.

Beneath the specimens are labels telling us about where they were collected, when and who by, and who determined which species it is.

Beneath the specimens, labels tell us where they were collected, when, who by, and who determined which species it is.

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Types are flagged up by special labels – pink for holotypes, cream for paratypes.

Accession numbers attached to the pins.

First job – attach unique accession numbers to the type specimens.

Information from the labels was transferred to the catalogue –

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The labels make fascinating reading – some of the earliest species for which types are represented here were described in the first few years of the 20th century.  Its likely they were collected years before publication, making them well over 100 years old.  Some were gathered by individuals, others by scientific expeditions.  There is hardly anywhere they do not come from.   Going through species alphabetically, even before we get into the ‘D’s we have such locations as:

Congo Guinea Colombia Kaschmir
Uttar Pradesh, India Venezuela Gabon New Caledonia
Burma Phillipines Kenya Dutch New Guinea
Nigeria Argentina Peru S. Rhodesia
South Africa Ecuador Zaire San Francisco
Cameroon Panama Sierra Leone Ceylon
Sudan Lesser Sunda Islands Bolivia Sarawak
Madagascar Uluguru Mts, Tanganyika Seychelles Uganda
New Hebrides Bhutan Sumatra Costa Rica

The reference for the original publication of each species was checked (the first line under the bold heading) and an initial foray made into identifying their current taxonomy.    For some of the species, many revisions have been made to their taxonomic name since their original description.  Ensuring this information is correct will be a much longer project for someone else.

Thanks are due to Dr Dmitri Logunov, Curator of Arthropods, for suggesting and guiding me through the project.