Adventures in Seaweeds

Having failed to start a proper regime in sourcing, pressing, drying and mounting Herbarium specimens (5% of our overall grade), I took a calculated risk and went to sea.

Encouraged that no Herbology student had done any before (great, no comparisons) and that both the products and processes were within reach, I set off to capture our underwater garden. 

But how? The Herbarium staff recommended floating seaweed in the bathtub and then lifting them out onto a bit of muslin cloth. Having only seen Victorian collages of floriforous concoctions, that didn’t seem too easy. Ally came to my rescue with a link to the Cryptogamic Botany Company who had a 7 page manual on ‘How to’.

The process is simple (relatively):

1.     Collect seaweed at low tide from pools, sand, stones or rocky shore. Keep in separate plastic bags of sea water (soon abandoned for 1 large bucket) and take note of where it was growing, holdfast, location and date, etc

2.     Collect additional bottles of seawater for cleaning and processing

3.     Wash a large 3” deep tray (type used for old-fashioned photography developing) and fill with about ¼ inch filtered sea water

4.     Soak your Herbarium paper face down and then turn right side up in tray, so only just covered in nanometre of water

5.     Clean seaweed specimen of all sand, grit, snails, other seaweeds and gunge and lay on paper.

6. Using tweezers, toothpicks, paintbrushes, fingers and gravity, arrange specimen to best advantage, removing stray and overlapping bits.

7.     Pull paper from tray (seaweed should stay put by osmotic force)  and drain water at shallow angle

8.     Place on pile of dry newspaper, make any final tweaks to arrangement, cover with muslin cloth, more newsprint and press down to remove as much water as possible.

9.     Place paper with muslin still on it in your press with new blotting paper and newsprint to absorb residual water.

10.   Cover press with stones/ irons/ heavy objects found in greenhouse and leave to dry 2 hours.  Change newsprint again, then leave to dry for 2-3 days for thin seaweeds, a week or more for thick ones.

The joy was that all of that is transcendental…

The problem came when trying to identify them…. whoops (add to number 1 on list above, ‘ only collect seaweed that you can reasonably identify’.  I read and re-read every page of Hamlyn’s Guide to Seasides and Shallow Waters (thanks for that, Greg) and then started on the internet.  There are lots of sites and lots of experts out there, but sometimes they don’t confer, so a seaweed identified as Rhodomenia psuedopalmata on one site is listed as Rhodomela lacinata on another and Palmaria palmata on another.  And do you know how many Polysiphonias there are???

I headed back to the RBGE and the voices of reality.  Deep in the caverns of the Herbarium, I delved out the ancient tomes of collectors of days gone by. Here there is a plethora of specimens (in varying states) from England, Wales, Ireland and Scotland and within the latter from Dunbar to South Ronalsdsay, Orkney.  Collections from the 1820’s were some of the best, but how charming to find ones collected by Roy Watling (now Professor of Mycology). Even within the hallowed halls of the RBGE there was some dissent on identifications,  but I put it down to evoloution and several trips later, I took the plunge and started labeling.  

And here they are!