Warning This Web page has been archived on the Web.

Archived Content

Information identified as archived on the Web is for reference, research or recordkeeping purposes. It has not been altered or updated after the date of archiving. Web pages that are archived on the Web are not subject to the Government of Canada Web Standards. As per the Communications Policy of the Government of Canada, you can request alternate formats on the Contact Us page.

Other Broadleaf Foliar Diseases

Several other fungal diseases affecting the foliage of broadleaf trees are common throughout B.C. In general these diseases cause little damage in natural forests, but localized epidemics can result in significant economic loss in stands of broadleaf trees under intensive management.

 

Fungal Organism

B.C. Hosts

Identification

Ciborinia whetzelii (Seaver) Seaver

aspen, cottonwood

Sclerotia form dark "inkspots" on living leaves that drop out in late summer leaving "shotholes" (Fig. 62a).

Didymosporiu m arbuticola Zeller

arbutus

Leaf spots, brown with purplish to reddish margins, 3-6 mm diameter form on living leaves (Fig. 62b).

Discula destructiva Redlin

dogwood

Tan-coloured spots and necrotic blotches form on leaves (Fig. 62c). Infections often progress to shoots and stems

Marssonina populi (Lib.) Magnus
teliomorph = Drepanopeziz a populorum (Demaz.) Höhn.

aspen, cottonwood, hybrid poplars

Diffuse orange-brown spots, 2-5 mm diameter, coalesce into vein-limited blotches (Fig. 62d).

Linospora tetraspora G. E. Thompson

cottonwood, balsam poplar

Irregular blotches of brownish grey discoloured tissue along leaf veins. Scattered black stromata appear as black dots, 0.1 mm diameter (Fig. 62e).

Mycosphaerel la populicola G. E. Thompson
anamorph = Septoria populicola Peck

balsam and hybrid poplars, rarely aspen

Circular black leaf spots form on both sides of leaves (Fig. 62f).

Rhytisma punctatum (Pers.:Fr.) Fr.

bigleaf maple

Stromata appear as "tar spots" on roughly circular areas of chlorotic leaf tissue (Fig. 62g).

Rhytisma salicinum (Pers.:Fr.) Fr.

willow

Black stromata with raised centers 2-5 mm diameter form on upper leaf surfaces (Fig. 62h).

Taphrina populi-salicis Mix

cottonwood, willow

Golden-yellow leaf spots (Fig. 62i).

Uncinula bicornis (Wallr.:Fr.) Lév

maple

Powdery white mycelium appears on leaf surface(s) in late summer and fall (Fig. 62j).


References:

Funk, A. 1985. Foliar fungi of western trees. Can. For. Serv., Inf. Rep. BC-X-265.


Figures

Click on any image to see the full size version.
Press "Back" on your browser to return to this screen.


Sclerotia of Ciborinia whetzelii on aspen - Click to see a larger version of this image

Figure 62a: Sclerotia of Ciborinia whetzelii on aspen.

 

 

Leaf spots on arbutus caused by Didymosporium arbuticola - Click to see a larger version of this image

Figure 62b: Leaf spots on arbutus caused by Didymosporium arbuticola.

 

 

 

Dogwood anthracnose caused by Discula destructiva - Click to see a larger version of this image

Figure 62c: Dogwood anthracnose caused by Discula destructiva.

 

 

 

Leaf spot symptoms on hybrid poplar - Click to see a larger version of this image

 

Figure 62d: Leaf spot symptoms on hybrid poplar caused by Marssonina populi.

 

 

Stromata of Linospora tetraspora on discoloured leaf tissue - Click to see a larger version of this image

Figure 62e: Stromata of Linospora tetraspora on discoloured leaf tissue.

 

 

 

 

 

Leaf spots on hybrid poplar - Click to see a larger version of this image

Figure 62f: Leaf spots on hybrid poplar caused by Mycosphaerella populicola.

 

 

 

 

Stromata of Rhytisma punctatum on bigleaf maple - Click to see a larger version of this image

Figure 62g: Stromata of Rhytisma punctatum on bigleaf maple.

 

 

 

Stromata of Rhytisma salicinum on willow - Click to see a larger version of this image

Figure 62h: Stromata of Rhytisma salicinum on willow.

 

 

 

Leaf spots caused by Taphrina populina - Click to see a larger version of this image

 

Figure 62i: Leaf spots caused by Taphrina populina (similar to Taphrina populi-salicis) on cottonwood.

 

 

Uncinula bicornis on bigleaf maple - Click to see a larger version of this image

Figure 62j: Uncinula bicornis on bigleaf maple.