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.

Ouzels and Sprites

Last weekend was a great one for birding. Saturday started drizzly and it continued like that for the rest of the day, but when I saw news of a Yellow-browed Warbler just 10 minutes away I couldn’t resist going for this scarce vagrant. When we arrived at Bewbush West Playing Fields it was cloudy and miserable. We could tell that this wasn’t the most likely destination for most birders, it was simply a few football pitches, a tiny section of woodland and a hedgerow.

We followed a footpath adjacent to the playing fields, as that was where the Yellow-browed Warbler was seen. Along the whole route I played the call of this species, hoping that the lost bird would call back and reveal its presence. We had no luck for the first fifteen minutes, with only Blue Tits and Robins calling from the trees. However, as we reached a large, dense, berry-laden Hawthorn bush, my mum and I both heard the call. ‘Tseeweest, tseeweest’. That was the bird! I played back the call several times and received a couple more faint responses, but that was it. There was no sign of the bird, it was obviously well hidden inside the dark, dark hedge.

Yellow-browed Warblers are birds that breed in Siberia and winter in South-east Asia, but hundreds each year perform ‘reverse migration’, that is migrating in the wrong direction, and find themselves here in Britain. This is the perfect time of year for these Siberian ‘sprites’ to turn up on our coasts, with a maximum of 600 on one day earlier this year. All records are pretty much confined to the east coast, however, with few making their way inland. This year has so far been a bumper year for them, with 8 being seen in Surrey at the time of writing. Considering that there haven’t been any confirmed records for at least 2 years this is amazing!

The next day the weather was much more favourable and my dad and I made our way to the brilliant Ashdown Forest to see how Autumn was getting on. There had been 12 Ring Ouzels reported during the last two days and these are another species I had yet to see in Britain and indeed the world. When we arrived in the car park we could simply hear autumn calling from the trees: there were Chaffinches everywhere! Given this being a bumper year for beech mast, one of their favourite foods, I wasn’t too surprised to see lots. However, I think 69 is a pretty good total!

Continuing along the tarmac road I heard a distant Pheasant and party of Blackbirds in a dense holly bush. For a moment I thought I could hear a faint ‘chack’ of a Ring Ouzel, but I couldn’t be sure. Further along the road we came to a more open area with gorse and some isolated pines. Ahead of us on the path we could see a flock of about 20 Chaffinches; however they were very flighty and I couldn’t tell if there were any Brambling among them. It didn’t sound like it, no Brambling calls stood out as the flock flew over our heads and into some tall pines at the bottom of a short slope.

A short while later, as we were under the cover of some tall pines and beech trees again, I spotted a flock of thrush-size birds flying around a small Rowan. They weren’t close and even through my binoculars I couldn’t tell if they were Blackbirds or Ring Ouzels; however it seemed unlikely that Blackbirds would form such a large flock. Retracing our steps we managed to find a path that lead down towards the Rowan for us to get a closer look and confirm the identity of those birds. It was a steep but easy descent, in one place we had to move quickly as we came across a huge Wood Ant nest!

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Formica rufa, Southern Wood Ant, nest

The number of birds around us was incredible. A tit flock made their way through the thin birch trees, hanging from the flimsy twigs. It was mainly made up of Long-tailed Tits, however there were also Blue, Coal and Great Tits along with seven Chiffchaffs. Several Redwings passed overhead and there were even more Chaffinches and Goldfinches calling from above.

We soon got to a point where we could see the bush where we had seen the Ring Ouzels feeding. There was clearly a lot of activity on the small Rowan and I was pleased to see, through my binoculars, that they were definitely Ring Ouzels! They were very busy feeding on the ripe red berries, along with many Chaffinches. Three Bramblings were also a nice surprise feeding on the berries, they are my first this winter and always great to see. This year I am trying to attract them in to our garden, but there hasn’t been much luck yet unfortunately.

Ring Ouzels are migrants that breed here in the UK in hilly and mountainous open areas. They don’t usually breed in South-East England so this time of year when they are passing through on their way to their wintering grounds is the best to see them. They are similar in appearance to Blackbirds being primarily black, however the males are easy to tell apart due to the bright white crescent on the breast. All genders and ages have this white crescent however it is duller in the females and especially so in juvenile birds. In cases where the crescent is faint, then the next best method of identification is looking at the wings. In Ring Ouzels, the wing is paler than the rest of the body and almost appears translucent, whereas in Blackbirds they are completely black in the males or uniformly dark brown.

Ring Ouzels are sadly declining in the UK and they have been given the red status. However there isn’t a clear cause of the decline and there are several groups working on researching this species and finding out why populations have decreased so much. However, the least numbers of birds have been recorded after warm summers, suggesting that a lack of food might be the problem. With an ongoing trend of warm weather due to global warming it is likely that the decline will continue.