Starting a Herbarium

For centuries botanists have been collecting specimens of the plants they observe. If done correctly, botanical specimens can last for a very long time. For example, the Angela Marmont Centre at the Natural History Museum has specimens collected by Charles Darwin and Alfred Russel Wallace. Specimens can be very useful in documenting regional variation and how a species has changed over time.

Last weekend I was out with the South-east branch of the British Bryological Society recording mosses and liverworts at Devil’s Dyke, north of Brighton. As is often the case, however, one of the highlights of this field trip was in fact not to do with the subject of our search! Once we had passed through a section of Ash woodland on our walk we came to a lovely crystal-clear chalk pond. Despite few bryophytes around the pond’s edges the pond was full of life, including several water plants. Most common was the Ivy-leaved Duckweed, Lemna trisulca, and there were also a few Potamogeton natans plants as well. However what really caught our eye was a very beautiful looking pondweed with a lovely texture and colour that was unfamiliar to me but not for the other members. They identified the pondweed as Groenlandia densa, otherwise known as the Opposite-leaved Pondweed.

Groenlandia densa is not a very common species and is sadly declining in Britain. This is mostly due to urbanisation, and therefore it is missing from the vast majority of London. It has also declined due to a factor known as eutrophication which is the presence of excessive nutrients in a water body. This is most commonly caused by run-off from the nearby land, and it creates a dense growth of plant life which can potentially displace species that cannot compete. Due to this decline, it was suggested that I collect a piece of the pondweed, in case it becomes a very rare species and little material for herbariums could be found without damaging a population.

It is easy for anyone to start preparing plant specimens; little specialist equipment is needed. This is all that is needed for a beginner to make a good quality specimen:

  • newspaper
  • heavy books
  • a dry environment
  • good quality card
  • PVA glue
  • printed labels

And these are the steps I went through to create my pondweed specimen:

  1. Lay out the specimen on half of a full double page spread of newspaper in a way that should show as many features as possible.
  2. Once the plant is in a good position, fold over the other page of the double page spread.
  3. Add some more sheets of newspaper to the top and bottom of the folded newspaper with the specimen inside.
  4. Put the newspaper on a hard, flat surface.
  5. Place a few heavy books on top of the newspaper.
  6. Leave the specimen until it is sufficiently dry and flat, this could take a few weeks or only a few days, but don’t overdo it and don’t leave it for too short a period.
  7. Once the specimen is ready carefully take it out from the newspaper and lay it out on your piece of card making sure that it shows the necessary features. Remember to leave room for a label!
  8. Using PVA glue or any other glue recommended by botanists, stick the specimen down on the card. PVA glue dries clear so don’t worry too much if you get some on the card where you don’t want it.
  9. Fill in a label. Ideally the label should show as much information about the plant as possible: species; family; collection number; locality (grid reference, name of site, nearest town, county etc.); habitat; collector’s name; date of collection; and also note down features of the plant that may have been lost in the drying process.
  10. Finally, and optionally, you could also attach a small paper envelope to the specimen containing dried fruit/seeds that would have been ruined in the pressing process.

And there you have your specimen! This is what my pondweed looked like before and after collecting, pressing and mounting:

This is not the only specimen I have so far collected. At the beginning of the summer, as part of my interest to record the slightly trickier-to-identify species, I collected a couple of Bramble (Rubus) species. These were the first specimens I collected and I was quite pleased with the result. However, they weren’t good enough. After I had dropped them off at the Angela Marmont Centre at the Natural History Museum, Dr David Allen kindly looked at them for me. Unfortunately they were lacking some necessary features vital in identification, such as a section of the first year growth. Using his advice, I went out recently and collected a specimen of a particularly late-flowering Bramble, and this was the result:

bramblespecimen

I will also attach with the specimen a couple of photos of the plant before it was collected:

This shall hopefully even further aid identification and maybe contribute to the understanding of this poorly known group.

Many groups are overlooked, because they are tricky to identify or they are too small or they need specialist equipment to collect. Some examples are dandelions, a nightmare of identification; desmids, microscopic algae; and parasitic wasps, also very difficult to identify. This results in these groups being little-known as few people are willing to try to find and identify them. This leads to under recording of species that are probably common, creating deceptive data. One of my aims is to try and master these very difficult groups and hopefully make a difference.

Advertisements

Invasion!

There is a very long list of species that are non-native to the UK, many (if not most) are harmful to our native wildlife. I am regularly finding non-native species in my garden as well as further afield, Grey Squirrels are one such example. They were introduced to the UK nearly a century and a half ago from North America and since then they have severely affected our native species, through the severe population decline in Red Squirrels to the predation of young birds and eggs.

You might remember that last year I found several individuals of the slug Ambigolimax nyctelius. It was the first record of this non-native species in Surrey and had most likely come from the nearby garden centre. Well, a few weeks ago I found a small black slimy flatworm under one of the logs in my garden, which upon closer inspection appeared to have two pale lines running down its body. I used this character to identify it, which wasn’t as tricky as I thought it might be. There are 14 species of terrestrial flatworms in the UK, however many are really distinctive, coloured bright yellow or with distinctive head shapes.

Looking through the species in this very helpful PDF, I could see only two species that looked similar to mine: Kontikia ventrolineata and Australopacifica coxii. I originally thought it might be Australopacifica coxii however when I looked closer I could see that on my specimen the two lines were grey and not blue as is more commonly found in that species. So I concluded that my flatworm was most likely to be Kontikia ventrolineata, however as I have never identified any flatworms before I sent a couple of photos to the leading expert on flatworms, Hugh Jones. To my delight he replied and said that there was no doubt that it was indeed Kontikia ventrolineata. He also sent two distribution maps, one before my record had been added and one with my record on the map. I am very pleased to say that this is the first time Kontikia ventrolineata has been recorded in Surrey!

Ever since I found that first Kontikia ventrolineata I have been seeing more and more under logs and stumps in my garden. This isn’t very good news, as this species is believed to prey on our native small snails and possibly slugs. Therefore the flatworms will be in competition with the thrushes and the hedgehogs, reducing the amount of food for them. They might be insignificant at the moment but if the numbers keep on increasing like they have already, then they will be a major blow for the hedgehog population especially.

DSCN7588

Only a week after I found the first Kontikia ventrolineata I found another alien species! This time it was found in our new beetle trap which is baited with bananas. It is tub shaped with a hole in the bottom through which the beetles enter and stay until I check it a few days later. The trap was full of many different types of fruit flies and several wasps but only one beetle, which would have been disappointing if it wasn’t an interesting species.

The beetle was tiny, but identification was aided by the interesting shape and the markings. After a lot of research I was able to narrow it down to a family, Nitidulidae, and from there I eventually reached species level and identified it as Carpophilus hemipterus, also known as the Dried Fruit Beetle. Its favourite food is overripe fruit, which explains its presence in the trap. Although it is native to Asia, it has spread all around the globe on exported fruit and now inhabits all continents apart from Antarctica! map

However, looking at the NBN Gateway map for this species (above) it doesn’t appear very common but seems widespread, at least in England. The NBN Gateway doesn’t always show all of the records of a species on the map, so I don’t know if this might be the first record for this species in Surrey outside of London, however it certainly isn’t common!

RSCN8316

Carpophilus hemipterus. Not the best photo: the beetle was really tiny!