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Brenneria salicis. Brenneria salicis is a Gram-negative bacterium that is pathogenic on plants . The bacterium is known to cause 'watermark disease' in willow ( Salix ssp.) trees. Watermark disease affects infected trees by occluding the xylem vessels, impeding circulation. Early signs of the disease are wilting or dried-out, dead leaves on ...
Corythucha elegans, the willow lace bug, is a bug species in the family Tingidae found on willows in North America. Rhabdophaga rosaria is a type of gall found on willows. Rust, caused by fungi of genus Melampsora, is known to damage leaves of willows, covering them with orange spots.
Salix alba 'Vitellina' ( golden willow; syn. Salix alba var. vitellina (L.) Stokes) is a cultivar grown in gardens for its shoots, which are golden-yellow for one to two years before turning brown. It is particularly decorative in winter; the best effect is achieved by coppicing it every two to three years to stimulate the production of longer ...
Description. Salix nigra is a medium-sized deciduous tree, the largest North American species of willow, growing to 10–30 m (35–100 ft) tall, exceptionally up to 45 m (148 ft), with a trunk 50–80 centimeters (20–30 in) diameter. The bark is dark brown to blackish, becoming fissured in older trees, and frequently forking near the base. [ 3]
Symptoms include mosaic pattern on the leaves, malformed leaves and flowers, elongated shoots that are often red, and sometimes thorn proliferation. The distorted growth may be mistaken for herbicide damage. [12] There is no treatment for the disease, and control is limited to controlling the vector and destroying infected plants.
Chamaenerion angustifolium. ( L.) Scop. Chamaenerion angustifolium is a perennial herbaceous flowering plant in the willowherb family Onagraceae. It is known in North America as fireweed and in the British Isles as rosebay willowherb. [ 1] It is also known by the synonyms Chamerion angustifolium and Epilobium angustifolium.
Salix lasiolepis is a deciduous large shrub or small multi−trunked tree growing to 10 metres (33 ft) tall. The shoots are yellowish brown and densely hairy when young. The leaves are 3.5–12.5 centimetres (1.4–4.9 in) long and broadly lanceolate in shape. They are green above and glaucous green below.
Leaf spot. A leaf spot is a limited, discoloured, diseased area of a leaf that is caused by fungal, bacterial or viral plant diseases, or by injuries from nematodes, insects, environmental factors, toxicity or herbicides. These discoloured spots or lesions often have a centre of necrosis (cell death). [ 1] Symptoms can overlap across causal ...