Mammillaria johnstonii
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| ( Britton & Rose ) Orcutt |
Mammillaria johnstonii is a species of the genus Mammillaria in the cactus family(Cactaceae). The specific epithet honors the American botanist Ivan Murray Johnston .
description
Mammillaria johnstonii usually grows singly, occasionally sprouting from the base. The spherical to short cylindrical shaped, cloudy bluish-gray-green shoots are 15 to 20 centimeters high. The square warts contain milk juice . The axillae remain naked. The 2 central spines , rarely 4 to 6, are bluish-brown, straight, one protruding and spreading the others. They become 1 to 2.5 inches long. The 10 to 14 radial spines are needle-like, stiff, white with a brown tip. They are 6 to 9 millimeters long.
The flowers are white to light pink or cream-colored with pink to brownish central stripes. They grow up to 2 centimeters in diameter. The scarlet fruits are swollen to a spherical shape. They contain brown seeds .
Distribution, systematics and endangerment
Mammillaria johnstonii is widespread in the Mexican state of Sonora in the Bahia San Carlos.
The first description was in 1923 as Neomammillaria johnstonii by Nathaniel Lord Britton and Joseph Nelson Rose . Charles Russell Orcutt combined the species into Mammillaria in 1926 . Synonyms are: Neomammillaria johnstonii Britton & Rose (1923) and Mammillaria johnstonii var. Sancarlensis R.T. Craig (1945).
In the Red List of Threatened Species of IUCN is the species as " Endangered (EN) ," d. H. listed as endangered.
proof
literature
- Edward F. Anderson : The Great Cactus Lexicon . 2nd Edition. Eugen Ulmer KG, Stuttgart 2011, ISBN 978-3-8001-5964-2 , pp. 389 .
- Robert T. Craig : The Mammillaria handbook: with descriptions, illustrations, and key to the species of the genus Mammillaria of the Cactaceae . EP Publishing, University of Wisconsin, Madison 1963, ISBN 0-85409-330-3 , pp. 98-99 .
- Ulises Guzmán: Catálogo de cactáceas mexicanas . Universidad National Autonoma de México, Mexico City 2007, ISBN 970-9000-20-9 , pp. 134 .
Individual evidence
- ↑ Urs Eggli, Leonard E. Newton: Etymological Dictionary of Succulent Plant Names . Birkhäuser 2004, ISBN 3-540-00489-0 , p. 122.
- ^ NL Britton , JN Rose : The Cactaceae. Descriptions and Illustrations of Plants of the Cactus Family . tape IV . The Carnegie Institution of Washington, Washington 1923, p. 80-81 ( online ).
- ↑ Cactography . National City and San Diego, CA 1926, p. 7.
- ↑ Mammillaria johnstonii in the IUCN Red List of Threatened Species 2013.2. Posted by: Burquez Montijo, A. & Felger, RS, 2010. Retrieved December 27, 2013.