Gwymon a Lewis Weston Dillwyn

Chara globularis

Chara globularis, rhywogaeth Charophyte cyffredin sydd i’w gweld mewn cynefinoedd dŵr ffres a lled hallt.

Pwll glan môr ym Mhorthcawl, de Cymru gyda gwymon Ulva gwyrdd.


Gwymon amrywiol ym Mae Breichled, Penrhyn Gŵyr.

Seaweeds are found in abundance around the coasts of Wales. The temperate waters have a large tidal range which creates ideal conditions for seaweeds. Amgueddfa Cymru’s seaweed collection is mainly British material, and although not large, contains around 422 species and represents two thirds of all British seaweeds.

Within the collections, there are representatives of some UK Biodiversity Action Plan seaweed species, for example Anotrichium barbatum (a red seaweed) and Phymatolithon calcareum (a coralloid red seaweed). The largest single collection of seaweeds at Amgueddfa Cymru is that of 1131 specimens purchased from E.M. Holmes in 1922.

Significant seaweed collections made by Sue Hiscock throughout Wales were purchased in the 1980’s and 90’s by Amgueddfa Cymru. Sue Hiscock is the author of the popular British Seaweed Field Keys produced by the Field Studies Council. Included in the collections were specimens from detailed surveys to map the seaweeds of Skomer Island from intertidal and subtidal habitats. Skomer Island off Pembrokeshire is renowned for its marine life and is one of only three Marine Nature Reserves in the UK.

For display and teaching purposes, Amgueddfa Cymru holds models of seaweeds, both made from wax and those made from actual specimens. These include common species such as Ascophyllum nodosum, Fucus serratus, F.spiralis, F.vesciculosus, Laminaria digitata, Palmaria palmata and Pelvetia canaliculata as well as others on permanent display in the extensive Natural History Galleries.

In the botanical illustrations library we hold a set of 221 beautiful colour plates used in the publication of Nature Printed British Seaweeds by Johnstone and Croall (1860).

Lewis Weston Dillwyn

Amgueddfa Cymru holds Lewis Weston Dillwyn’s ‘Herbarium British Confervae’, a book containing 277 algal specimens Dillwyn amassed. He is an important figure in Welsh history and many of the specimens he collected were from or near Swansea where he lived. The herbarium contains specimens which are the original material used by Dillwyn in the preparation of his pioneering 1809 work on British Confervae. (Conferva is an old name for filamentous algae. These can be freshwater or marine, and include some seaweeds. Linnaeus used Conferva as the genus name for that group, as did Dillwyn. However, filamentous algae have since been split into many different groups). This work, a rare copy of which is housed in Amgueddfa Cymru, contains beautiful colour drawings of algae and was a significant step for algology. Before its publication, there had been only 34 species described, this jumped to 177 described species after its publication. This is an important exsiccatae in our collection which may include a substantial number of type specimens.

The museum also holds substantial molluscan specimens collected by Lewis Weston Dillwyn.