Uropyxis petalostemonis
| Uropyxis petalostemonis | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Uropyxis petalostemonis | ||||||||||||
| ( Farl. ) De Toni |
Uropyxis petalostemonis is a stand fungal art from the order of the rust fungi (Pucciniales). The fungus is an endoparasite of the legume genus Petalostemon . 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
Uropyxis petalostemonis 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 Uropyxis petalostemonis , like all Uropyxis species, grows intercellularly and forms suction threads that grow into the host's storage tissue. Their spermogonia grow on the underside in small groups on the host leaves, sometimes also on stems. The aecia of the species growing between them have colorless paraphyses. Their yellowish aeciospores are 26–32 × 17–20 µm in size, ovate to ellipsoidal and spiky. The uredia of the fungus resemble its aecia, also in their spores. The parts of the species growing underneath the leaves are chocolate brown to blackish, powdery and uncovered. The chestnut-brown teliospores are two-celled, generally ellipsoidal to long-ellipsoidal, spiky and usually 36–42 × 23–27 µm in size. Their stem is colorless.
distribution
The known distribution area of Uropyxis petalostemonis stretches from southern Canada to the southern USA .
ecology
The host plants of Uropyxis petalostemonis are diverse Petalostemon 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 macrocyclical development cycle with Spermogonia, Aecien, Telien and Uredien. As an auto-ecologic parasite, it does not 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 .