Uromyces minimus
| Uromyces minimus | ||||||||||||
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| Scientific name | ||||||||||||
| Uromyces minimus | ||||||||||||
| Davis |
Uromyces minimus is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is an endoparasite of sweet grasses of the genus Muehlenbergia . Symptoms of the infestation by the species are rust spots and pustules on the leaf surfaces of the host plants. It occurs in the northern United States .
features
Macroscopic features
Uromyces minimus can only be recognized with the naked eye by means of 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 minimus grows as with all Uromyces TYPES intercellular and forms Saugfäden that grow into the storage tissue of the host. The small, golden to cinnamon-brown uredia of the fungus grow on the underside of the host leaves. Their cinnamon-brown uredospores are 17–21 × 16–18 µm in size, mostly egg-shaped to spherical and spiky. The parts of the species, mostly growing on the upper side of the leaf, are black-brown, compact and uncovered early. The chestnut-brown teliospores are unicellular, usually ovate to narrow-oval and 19–24 × 14–17 µm in size. Their stem is colorless to tinted and up to 40 µm long.
distribution
The known distribution area of Uromyces minimus extends from Oregon to Michigan .
ecology
The host plants of Uromyces minimus are Muehlenbergia andina , M. racemosa and M. sylvatica . 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 development cycle of which only Telien and Uredien and their host are known; Spermogonia and aecia are so far unknown.
literature
- George Baker Cummins: The Rust Fungi of Cereals, Grasses and Bamboos . Springer, Berlin 1971, ISBN 3-540-05336-0 .