Uromyces mexicanus
| Uromyces mexicanus | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Uromyces mexicanus | ||||||||||||
| Dietel & Holw. |
Uromyces mexicanus is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is an endoparasite of the legume genus Desmodium . Symptoms of the infestation by the species are rust spots and pustules on the leaf surfaces of the host plants. It is common in North America .
features
Macroscopic features
Uromyces mexicanus can only be recognized with the naked eye by the spore beds protruding on the surface of the host. They grow in nests that appear as yellowish to brown spots and pustules on the leaf surfaces.
Microscopic features
The mycelium of Uromyces mexicanus grows as with all Uromyces TYPES intercellular and forms Saugfäden that grow into the storage tissue of the host. The spermogonia and aecia of the species are unknown. The uredia of the fungus growing on the underside of the surfaces of the host leaves are cinnamon-brown and have colorless paraphyses. Their uredospores are 21–24 × 17–20 µm in size, mostly broadly ellipsoidal and spiky. The parts of the species, which usually grow on the underside of the surfaces of the host leaves, are cinnamon-brown, loosely to densely grouped, compact and uncovered. The chestnut-brown teliospores are unicellular, usually ovoid to ellipsoid, warty and mostly 23–28 × 17–20 µm in size. Their stalk is almost hyaline and up to 100 µm long.
distribution
The known distribution area of Uromyces mexicanus extends from central Mexico to Arizona and New Mexico .
ecology
The host plants of Uromyces mexicanus are different Desmodium species. The fungus feeds on the nutrients present in the storage tissue of the plants, its spore beds later break through the leaf surface and release spores. The species goes through a probably macrocyclical development cycle of which only uredia and telia and their host are known so far. It cannot therefore be said whether she will change host .
literature
- George Baker Cummins : Rust Fungi on Legumes and Composites in North America . University of Arizona Press, Tucson 1978, ISBN 0-8165-0653-1 .