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Laurencia Hybrida
''Osmundea hybrida'' is a fairly small marine red alga. Description ''Osmundea hybrida'' is small branched alga which grows from a holdfast to 15 mm long. The axes show a main axis with branches which may be spiral or irregular. The main axis may be slightly compressed with a medulla of cells surrounded by a cortex deep purplish-brown in colour. A small circular pit occurs at the apex of the branches.Maggs, C.A. and Hommersand, M.H.1993 ''Seaweeds of the British Isles Volume 1 Rhodophyta Part 3A Ceramiales'' Habitat Common but not as common as '' Osmundea pinnatifida''. Epilithic in the littoral on stones, rock and on limpets. Reproduction Spermatangial receptacles, where the male gametes occur in small cups, are at the end of the side branches. Cystocarps are spherical and sessile and tetraspores are produced in small branchlets. Distribution This alga is to be found all around the British Isles as far north as Shetland Shetland, also called the Shetland Island ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alga
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as ''Chlorella,'' ''Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and autotrophic (they generate food internally) and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the ''Charophyta'', a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. No definition of algae is generally accepted. One definition is that algae "have chlorophyll ''a'' as their primary photosynthetic pigment and lack a sterile covering of cells around t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holdfast (biology)
A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate. Holdfasts vary in shape and form depending on both the species and the substrate type. The holdfasts of organisms that live in muddy substrates often have complex tangles of root-like growths. These projections are called haptera and similar structures of the same name are found on lichens. The holdfasts of organisms that live in sandy substrates are bulb-like and very flexible, such as those of sea pens, thus permitting the organism to pull the entire body into the substrate when the holdfast is contracted. The holdfasts of organisms that live on smooth surfaces (such as the surface of a boulder) have flattened bases which adhere to the surface. The organism derives no nutrition from this intimate contact with the substrate, as the process of liberating nutrients from the substrate requires ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmundea Pinnatifida
''Osmundea pinnatifida'' is a species of red alga known by the common name pepper dulse. It is a small seaweed widely found with the tidal zone of moderately sheltered rocky shores around Britain and Europe. Although technically a red seaweed, it can show a wide range of colouring from yellow-buff to a red so dark as to be almost black. Description ''Osmundea pinnatifida'' is a small marine alga which grows in tufts with branches to a length of 8 cm from a discoid holdfast which produces of stolons for further support. The fronds are flattened with a medulla of thick cells covered by a cortex of 2 layers. The branches are alternate, flattened and branching in one plane from the sides one or two times. The axes show a small terminal groove at the apex.Maggs, C.A. and Hommersand, M.H. 1993. ''Seaweeds of the British Isles Volume 1 Rhodophyta Part 3A Ceramiales'' The Natural History Museum, London Bunker, F.StP.D., Brodie, J.A., Maggs, C.A., Bunker, A.R.2017. ''Seaweeds of Brita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Isles
The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, and over six thousand smaller islands."British Isles", ''Encyclopædia Britannica''. They have a total area of and a combined population of almost 72 million, and include two sovereign states, the Republic of Ireland (which covers roughly five-sixths of Ireland), and the United Kingdom of Great Britain and Northern Ireland. The Channel Islands, off the north coast of France, are normally taken to be part of the British Isles, even though they do not form part of the archipelago. The oldest rocks are 2.7 billion years old and are found in Ireland, Wales and the northwest of Scotland. During the Silurian period, the north-western regions collided with the south-east, which had been part of a separate continental landmass. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shetland
Shetland, also called the Shetland Islands and formerly Zetland, is a subarctic archipelago in Scotland lying between Orkney, the Faroe Islands and Norway. It is the northernmost region of the United Kingdom. The islands lie about to the northeast of Orkney, from mainland Scotland and west of Norway. They form part of the border between the Atlantic Ocean to the west and the North Sea to the east. Their total area is ,Shetland Islands Council (2012) p. 4 and the population totalled 22,920 in 2019. The islands comprise the Shetland (Scottish Parliament constituency), Shetland constituency of the Scottish Parliament. The local authority, the Shetland Islands Council, is one of the 32 council areas of Scotland. The islands' administrative centre and only burgh is Lerwick, which has been the capital of Shetland since 1708, before which time the capital was Scalloway. The archipelago has an oceanic climate, complex geology, rugged coastline, and many low, rolling hills. The lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portugal
Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of the Azores and Madeira. It features the westernmost point in continental Europe, and its Iberian portion is bordered to the west and south by the Atlantic Ocean and to the north and east by Spain, the sole country to have a land border with Portugal. Its two archipelagos form two autonomous regions with their own regional governments. Lisbon is the capital and largest city by population. Portugal is the oldest continuously existing nation state on the Iberian Peninsula and one of the oldest in Europe, its territory having been continuously settled, invaded and fought over since prehistoric times. It was inhabited by pre-Celtic and Celtic peoples who had contact with Phoenicians and Ancient Greek traders, it was ruled by the Ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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