Dulse

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Palmaria palmata

Scientific classification

Kingdom:	Protista
Phylum:	Rhodophyta
Class:	Florideophyceae
Order:	Palmariales
Family:	Palmariaceae
Genus:	Palmaria
Species:	P. palmata

Binomial name

Palmaria palmata
(Linnaeus) Kuntze, 1891

Dulse (Palmaria palmata (L.) Kuntze), also called dillisk, dilsk, dulse or creathnach, is a red alga (Rhodophyta) that grows on the northern coasts of the Atlantic and Pacific oceans, it is a well-known snack food. In Iceland, where it is known as söl, it has been an important source of fiber through the centuries, but is now consumed as snack food.

1 Description
2 Reproduction
3 Ecology
4 Food
5 Distribution
6 Infections, galls, malformations and diseases
7 References
8 Further reading
9 External links

[edit] Description

Dulse grows attached by its discoid holdfast to the stipes of Laminaria or to rocks. It has a short stipe, the fronds are very variable and vary in colour from deep-rose to reddish-purple in colour and rather leatherly in texture. The flat blade gradually expands and devides into broad segments ranging in size to 50 cm long and 30 - 8 cms in width. The flat frond is wedge-shaped with branches or proliferations from the edge. Dulse is similar to another seaweed Dilsea carnosa, Dilsea, however, is more leathery with bladed up to 30cms long and 20cms wide. Unlike Palmaria palmata it is not branched and does not have proliferations or branches from the edge of the frond.

[edit] Reproduction

The full life-history was not fully explained until 1980.^[1] Tetraspores occur in scattered sori on the mature blade and spermatial sori occur scattered over most of the frond of the male plant. Carpogonial plants are very small stunted or encrusted, the carpogonia apparently occurring as single cells in ther young plants. After fertilization the diploid plant overgrows the female plant, grows and develops into the tetrasporangial diploid phase. It is therefore usually the diploid tetrasporic phase or the male plants which are found on the shore.^[2]

[edit] Ecology

Palmaria palmata is to be found growing between the mid-tide of the intertidal zone (the area between the high tide and low tide) to a depths of 20 m or more in both sheltered and exposed shores.^[2]

[edit] Food

It is commonly found from June to September and can collected by hand when the tide is out. When collected small snails, shell pieces and other small particles can be washed or shaken off and the plant then spread to dry. Some collectors may turn it once and roll it into large bales to be packaged later. It is also used as fodder for animals in some countries.

Dulse is commonly used in Ireland [1], Iceland and Atlantic Canada both as food and medicine. It can be found in many health food stores or fish markets and can be ordered directly from local distributors. In Ballycastle, Northern Ireland it is traditionally sold at the Ould Lammas Fair. A variety of dulse is cultivated in Nova Scotia and marketed as Sea Parsley, sold fresh in the produce section. Dulse is now shipped around the world.

Dulse can be found in some dietary supplements, where it is often referred to as "Nova Scotia Dulce", it is a good source of dietary requirements, a handful will provide more than 100% of the daily amount of Vitamin B6, 66% of Vitamin B12, a day's supply of iron and fluoride, and it is relatively low in sodium and high in potassium.

Fresh dulse can be eaten directly off the rocks before sun-drying. Sun-dried dulse is eaten as is or is ground to flakes or a powder. In Iceland the tradition is to eat it with butter. It can also be pan fried quickly into chips, baked in the oven covered with cheese with salsa, or simply microwaved briefly. It can also be used in soups, chowders, sandwiches and salads, or added to bread/pizza dough. Finely diced, it can also be used as a flavor enhancer in meat dishes, such as chili, in place of monosodium glutamate.

[edit] Distribution

Found on the coast of Europe including Portugal and the Baltic. It is also found on the coasts of Iceland, the Faeröes (Faroes),^[3] Arctic Russia, Arctic Canada, USA, both Atlantic and Pacific (New Jersey, Alaska to California), Japan and Korea.^[2]

[edit] Infections, galls, malformations and diseases

Galls, possibly produced by nematodes, copepods and bacteria are known to infect these plants. They were recorded as "outgrowths of tissue produced by the presence...of an animal."^[4]^[2]

[edit] References

^ van der Meer, J.P. and Todd, E.R. 1980. The life-history of Palmaria palmata in culture. A new type for the Rhodophyta. Can. J. Bot. 58: 1250 - 1256
^ ^a ^b ^c ^d Irvine, L.M. 1983. Seaweeds of the British Isles. Volume 1. Part 2A. Cryptonemiales (sensu stricto) Palamriales, Rhodymeniales. British Museum (Natural History), London. ISBN 0 565 00871 4
^ Borgesen, F. 1903. Botany of the Faeröes...Part II. Copenhagen (reprint 1970)
^ Barton,E.S. 1891. On the occurrence of galls in Rhodymenia palmata Grev. J.Bot. Lond. 29: 65 - 68

[edit] Further reading

Barton, E.S. 1891. On the occurrence of Galls in Rhodymenia palmata Grev. J. of Bot. 29: 65 - 68.
Grubb, V.M. 1923. Preliminary note on the reproduction of Rhodymenia palmata, Ag. Ann. Bot. 37 : 151 - 152.

Pueschel, C.M. 1979. Ultrastructure of the tetrasporogenesis in Palmaria palmata (Rhodophyta). J. Phycol. 15: 409 - 424.
South, G.R. and Hooper, R.G. 1980. A Catalogue and Atlas of the Benthic Marine Algae of the Island of Newfoundland. p. 1 - 136. Memorial University of Newfoundland Occasional Papers in Biology.