Ulva lactuca

Ulva lactuca Linnaeus, a green alga in the Division Chlorophyta, is the type species of the genus Ulva, also known by the common name sea lettuce.

Additional recommended knowledge

Daily Visual Balance Check

Guide to balance cleaning: 8 simple steps

How to ensure accurate weighing results every day?

Description

Ulva lactuca is a thin flat green alga growing from a discoid holdfast. The margin is somewhat ruffled and often torn. It may reach 18 cm or more long though generally much less and up to 30 cm across.^[1] The membrane is two cells thick, soft and translucent.^[2] and grows attached, without a stipe, to rock via a small disc-shaped holdfast.^[3] Green to dark green in color this species in the Chlorophyta is formed of two layers of cells irregularly arranged, as seen in cross section. The chloroplast is cup-shaped with 1 to 3 pyrenoids.

Distribution

New Zealand Plant^[4]

Ecology

Ulva lactuca is very common on rocks and on other algae in the littoral and sublittoral on shores all around the British Isles^[5] with a world-wide distribution.^[3] It is particularly prolific in areas where nutrients are abundant.^[6] There are other species of Ulva which are similar and not always easy to differentiate.

Life history

The sporangial and gametangial thalli are morphically alike. The diploid adult plant produces haploid spores by meiosis, these settle and grow to form haploid male and female plants similar to the diploid plants. When these haploid plants release gametes they unite to produce the zygote which germinates, and grows to produce the diploid plant.^[7][8][9]

Uses

U. lactuca is locally used in Scotland in soups and salads.^{[10] [11]}

References

Further reading

• Hayden, H.S., Blomster, J., Maggs, C.A., Silva, P.C., Stanhope, M.J. and Waaland, J.R. (2003) Linnaeus was right all along: Ulva and Enteromorpha are not distinct genera. Eur. J. Phycol. 38, 277-294.