The Algal Collection of the US National Herbarium (located in the National Museum of Natural History) consists of approximately 320,500 dried specimens, which, although not exhaustive (no exhaustive collection exists), gives an idea of the order of magnitude of the number of algal species (that number remains unknown). Estimates vary widely. For example, according to one standard textbook, in the British Isles the UK Biodiversity Steering Group Report estimated there to be 20000 algal species in the UK. Another checklist reports only about 5000 species. Regarding the difference of about 15000 species, the text concludes: "It will require many detailed field surveys before it is possible to provide a reliable estimate of the total number of species ...."
Regional and group estimates have been made as well:
- 5000–5500 species of red algae worldwide
- "some 1300 in Australian Seas"
- 400 seaweed species for the western coastline of South Africa, and 212 species from the coast of KwaZulu-Natal. Some of these are duplicates as the range extends across both coasts, and the total recorded is probably about 500 species. Most of these are listed in List of seaweeds of South Africa. These exclude phytoplankton and crustose corallines.
- 669 marine species from California (US)
- 642 in the check-list of Britain and Ireland
and so on, but lacking any scientific basis or reliable sources, these numbers have no more credibility than the British ones mentioned above. Most estimates also omit microscopic algae, such as phytoplankton.
The most recent estimate suggests a total number of 72,500 algal species worldwide.
Read more about this topic: Algae
Other articles related to "numbers":
... Five numbers were then aligned on the outside top of the square, and five numbers on the left side of the square vertically ... Usually these numbers were arranged 1 through 5 ... By cross-referencing the two numbers along the grid of the square, a letter could be deduced ...
... In abstract algebra terms, the dual numbers can be described as the quotient of the polynomial ring R by the ideal generated by the polynomial X2, R/(X2) ... With this description, it is clear that the dual numbers form a commutative ring with characteristic 0 ... Moreover the inherited multiplication gives the dual numbers the structure of a commutative and associative algebra over the reals of dimension two ...
... Most winter in that sea, but small numbers enter the Atlantic in late summer ... This is a gregarious species, which can be seen in large numbers from boats or headlands, especially in autumn ... historically and thus, while not threatened judging from its absolute numbers, could be vulnerable to adverse effects of inbreeding ...
... One application of dual numbers is automatic differentiation ... Consider the real dual numbers above ... it is straightforward to extend the domain of this polynomial from the reals to the dual numbers ...
... Please refer to the separate numbers article for details of how numbers work in Finnish ...
Famous quotes containing the word numbers:
“The principle of majority rule is the mildest form in which the force of numbers can be exercised. It is a pacific substitute for civil war in which the opposing armies are counted and the victory is awarded to the larger before any blood is shed. Except in the sacred tests of democracy and in the incantations of the orators, we hardly take the trouble to pretend that the rule of the majority is not at bottom a rule of force.”
—Walter Lippmann (18891974)
“All ye poets of the age,
All ye witlings of the stage,
Learn your jingles to reform,
Crop your numbers to conform.
Let your little verses flow
Gently, sweetly, row by row;
Let the verse the subject fit,
Little subject, little wit.
Namby-Pamby is your guide,
Albions joy, Hibernias pride.”
—Henry Carey (1693?1743)
“He bundles every forkful in its place,
And tags and numbers it for future reference,
So he can find and easily dislodge it
In the unloading. Silas does that well.
He takes it out in bunches like birds nests.”
—Robert Frost (18741963)