Black rust

Black rust is a disease that only occurs on wheat. It is caused by a fungus, Puccinia graminis. Puccinia is a genus of the order of the Rusts (Uredinales). The telia, in which the teliospores* are formed, are black. There are also other rust diseases, such as the yellow and brown rust, but the black variant is the most aggressive. The first sign that wheat has been contaminated with it, is a type of red, rusty blisters on the stem. Then the wheat grains shrivel, the stem bends, and eventually the plant dies and turns black.

A common pest

Rosebay willowherb or Fireweed - Chamerion angustifolium - is a very striking and widespread plant species. During flowering it is easy to recognize. The upright plants have a cluster-shaped inflorescence at the top that tapers to a point. The color of the flowers is purple or purple-red. The separate flowers in the cluster are somewhat symmetrical on both sides because the top two petals are somewhat smaller than the bottom two. The scattered leaves are narrow and lanceolate and closely resemble the leaves of Willows.

A pest on grapes

Uncinula necator or powdery mildew, a basidiomycete, is a pest on grapes. Its septate hyphae forms a mycelium on the surface of the leaves similar to a spider web. Special hyphal branches, the haustoria, penetrate the host cells to absorb food substances, thereby weakening the grape and reducing the harvest.

Pear rust and Junipers

Pear Rust is an increasingly common fungal disease in pear trees. This disease can significantly slow the growth of a pear tree, and the tree will also give less fruits. Pear Rust is a fungus that cannot stay the whole year on the pear: in winter the tree has no leaves and the fungus is only present there. In winter, the fungus needs a Juniper to overwinter. After the winter the fungus makes spores, which are spread through the air. The spores fall on the pear tree, causing the fungal disease.

Eating corn smut?

Common smut of corn, caused by Ustilago zeae (now known as U. maydis), is easily identified by tumor-like galls that form on actively growing host tissues and contain masses of dark, sooty teliospores.

Yellow, widespread and strong

Xanthoria parietina is a yellowy orange colored leafy lichen that is one of the most common species around. The yellow chemical xanthorin is thought to be produced as a defense against UV radiation to which it is exposed in its normal habitat like cement tiled roofs, exposed twigs and branches etc.