''Alaria marginata'', the winged
kelp
Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms.
Kelp grows in "underwa ...
, is a brown alga species in the genus ''
Alaria''. It can grow up to 13 feet.
Frond
A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the lar ...
s are long and narrow with raised midrib and wavy edges. Each frond has two rows of several smooth, oblong, 5 inch
spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...
-bearing blades at the base in winter.
According to a study done by Widdowson(1971), the kelp ''Alaria marginata'' has been known to occupy certain wave-exosed intertidal habitats. These habitats can be found in the northeast Pacific from
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
to near
Point Conception, California. ''Alaria marginata'' has been the dominant macroalga on this exposed mid-to-low rocky shores along the
Big Sur
Big Sur () is a rugged and mountainous section of the Central Coast of California between Carmel and San Simeon, where the Santa Lucia Mountains rise abruptly from the Pacific Ocean. It is frequently praised for its dramatic scenery. Big Sur ...
coast of California. The kelp commonly grows in large patches, which offers habitat and sustenance for tide pool organisms.
In the kelp species ''Alaria marginata'',
phenolics act as chemical defence against
herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...
s. Higher concentrations of the phenolics were found in the
reproductive fronds when compared to the vegetative blades, which were consumed at a higher rate by herbivorous
snails.
Seasonal changes
According to a study done by McConnico and Foster in the
Science Direct
ScienceDirect is a website which provides access to a large bibliographic database of scientific and medical publications of the Dutch publisher Elsevier. It hosts over 18 million pieces of content from more than 4,000 academic journals and 30 ...
, thinning of the kelp patches was inversely related to density. During the growing season from February to July, the kelp would grow in length up to 1.4 meters a month to form thick canopies.
The
sorus
A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores) in ferns and fungi. A coenosorus (plural coenosori) is a compound sorus composed of multiple, fused sori.
Etymology
This New Latin word is from Ancient Gr ...
development was found to be positively related to size and begins as early as March (peaking in late August-October). Releasing of the spores would take place most frequently between October and January, being associated with high water movement.
Harvesting and uses
Alaria marginata are an edible kelp, commonly harvested in the spring and early summer to avoid frond harm from the summer storms. The upper frond and midrib can be harvested, leaving the lower portion of the
frond
A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the lar ...
to continue to grow.
Once harvested, the alaria marginata can be used fresh or dried. To dry, fronds are hung off clotheslines for an even preservation of both sides of the kelp. The midrib of the alaria marginata can be cut out, separating the two opposing sheets and the stiffer midrib. Dried fronds can be stored in strips or pieces in a cool, dry place.
References
Further reading
*
*
*
*
External links
''Alaria marginata'' at www.algaebase.org
Alariaceae
Plants described in 1840
{{Phaeophyceae-stub