''Laminaria sinclairii'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

brown algae Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and po ...

(class Phaeophyceae), in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Laminariaceae Laminariaceae is a family of brown algal seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlor ...

. It is native to the lower intertidal zone of the northeastern Pacific Ocean from

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

southwards to

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

Description

This dark brown, perennial kelp grows from a creeping, branching

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

which sends up

thalli Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms were ...

at intervals. The thalli are ribbon-like and grow to a length of about and width of with a smooth surface and entire edges. They grow on short, cylindrical stipes some long and wide containing many

mucilage Mucilage is a thick, gluey substance produced by nearly all plants and some microorganisms. These microorganisms include protists which use it for their locomotion. The direction of their movement is always opposite to that of the secretion of m ...

ducts. It is very similar in appearance to ''

Laminaria longipes ''Laminaria'' is a genus of brown seaweed in the order Laminariales (kelp), comprising 31 species native to the north Atlantic and northern Pacific Oceans. This economically important genus is characterized by long, leathery laminae and relativ ...

'' but that species does not have mucilage glands in the stipes. In 1972, the American phycologist James W. Markham did some transplanting experiments to try to determine whether the presence of mucilage glands is a distinctive feature or the two species were identical. He found that they were indeed distinct and that there were some other differences between the two related to the width of blades, the shedding of the blades, the morphology of the reproductive structures, temperature tolerance and habitat preference.

Distribution and habitat

''Laminaria sinclairii'' is found in the northeastern Pacific Ocean, its range extending from

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian Provinces and territories of Canada, province of British Columbia. The island is in length, in width at its widest point, and in total area, while are o ...

in British Columbia, southwards to

Ventura County, California Ventura County () is a county in the southern part of the U.S. state of California. As of the 2020 census, the population was 843,843. The largest city is Oxnard, and the county seat is the city of Ventura. Ventura County comprises the Oxn ...

. It occurs on rocky substrates, sometimes partially covered in sand, in the lower part of the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

Ecology

This is the dominant seaweed on rocks in the lower part of the intertidal zone in Oregon on beaches where sand levels fluctuate dramatically at different times of year. In March and April new thalli appear from the rhizomes but these blades are progressively buried by rising sand levels which results in the complete burial of the plants over the summer. With the arrival of storms in the fall, the sand is scoured away and the thalli reappear. Reproductive sori are produced on the old blades before they are shed in December and on the new blades that grow in the spring.

References

{{Taxonbar, from=Q3216746 Laminariaceae