Lemanea is the generic name for an alga of which occurs in the British Isles.

There are two species in the British Isles:-

• Lemanea fluviatilis (L.) C.Ag.
• Lemanea fucina Bory

Lemanea is a freshwater alga, a species in the Phylum Rhodophyta (Red Algae

Red algae

The red algae are one of the oldest groups of eukaryotic algae, and also one of the largest, with about 5,000–6,000 species  of mostly multicellular, marine algae, including many notable seaweeds...

) of the Order Batrachospermales. Both species are considered to be widespread in the northern hemisphere. Although placed in the Rhodophyta (Red algae) it in fact is green in colour.

Description

Lemanea is a stiff bristle-like branched or unbranched plant similar to a coarse horsehair. Close inspection show it to have small swellings at more or less regular intervals along its length. It grows to 10 cm in length, in bunches in freshwater. It is blue-green to olive in colour when young.

Irish records

The records of this genus in Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 are few with only three historic records from the north of Ireland in the Ulster Museum

Ulster Museum

The Ulster Museum, located in the Botanic Gardens in Belfast, has around 8,000 square metres of public display space, featuring material from the collections of fine art and applied art, archaeology, ethnography, treasures from the Spanish Armada, local history, numismatics, industrial...

 Herbarium

Herbarium

In botany, a herbarium – sometimes known by the Anglicized term herbar – is a collection of preserved plant specimens. These specimens may be whole plants or plant parts: these will usually be in a dried form, mounted on a sheet, but depending upon the material may also be kept in...

 (BEL). One collected by William Thompson

William Thompson (naturalist)

William Thompson was an Irish naturalist celebrated for his founding studies of the natural history of Ireland, especially in ornithology and marine biology. Thompson published numerous notes on the distribution, breeding, eggs, habitat, song, plumage, behaviour, nesting and food of birds...

 in 1839; one collected by W. Sawers in 1856 and one collected in 1884 by H.W.Lett. These seem to be the earliest records from the north of Ireland. A more recent specimen collected in 1959 by Miss M.P.H. Kertland near Dungiven

Dungiven

Dungiven is a small town and townland in County Londonderry, Northern Ireland. It is on the main A6 Belfast to Derry road. It lies where the rivers Roe, Owenreagh and Owenbeg meet at the foot of the Benbradagh. Nearby is the Glenshane Pass, where the road rises to over...

, Co. Londonderry

County Londonderry

The place name Derry is an anglicisation of the old Irish Daire meaning oak-grove or oak-wood. As with the city, its name is subject to the Derry/Londonderry name dispute, with the form Derry preferred by nationalists and Londonderry preferred by unionists...

 is also preserved. A further 16 specimens collected recently, that is within the last 50 years, have been added to the collection - all from Northern Ireland

Northern Ireland

Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...

. We have one foreign specimen collected recently from the Faroes.
Recently Lemanea fucina has been reported from Clare Island.

In North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

four species in this genus are listed.

• Lemanea borealis Atkinson
• Lemanea fluviatilis (Linnaeus) C.Agardh
• Lemanea fucinia var. parva M.L. Vis & R.G. Sheath

World-wide 10 species are listed in algaebase:- http://www.algaebase.org/GeneraDetail.lasso?genus_id=42775&sk=0&-session=abv3:51909EC309e9f223AClpn34C41CE

• Lemanea borealis Atkinson
• Lemanea ciliata (Sirodot) De Toni
• Lemanea condensata Israelson
• Lemanea fluviatilis (Linnaeus) C. Agardh
• Lemanea fucina Bory de Saint-Vincent
• Lemanea fucina var. parva M.L.Vis & R.G. Sheath
• Lemanea mamillosa Kützing
• Lemanra rigida (Sirodot) De toni
• Laminea sinca C.C. Jac
• Lemanea sudeica Kützing

General references

• John, D.M., Whitton, B.A. and Brook, A.J. (Ed.) 2002. The Freshwater Algal Flora of the British Isles. Cambridge University Press.

• Morton, O 1978. Lemanea in the north of Ireland. Ir. Nat. J. 19: 205.

• Sawers, W. 1854. List of algae gathered in the north of Ireland. Naturalist, Morris 4: 254 - 257.

• West, G.S. and Fritsch, F.E. 1927. A Treatise on the British Freshwater Algae. Cambridge University Press, Cambridge. [Facsimile edition printed in 1968 as Vol. 3 of Bibliotheca Phycologia. J.Cramer, Lehre.]

Further reading

• Scannell, M.J.P. 1977. Localities in Cork East for Lemanea sp. (Rhodophycea) Ir. Nat. J. 19: 25.