Plant Disease Images


The images on this website are the property of the authors and may not be used without permission. All images were taken from samples received at the University of Maine Plant Diagnostic Clinic. Where image file names begin with a nine digit number, this number refers to a specific sample entered into the PDIS database and, therefore, all images prefixed by the same number are of the same organism. Although extensive effort has been made to correctly identify the organisms in these images, this is not a taxonomic treatise and some errors may occur. Please send any corrections or other input to

Click on the links below to view images of the signs/symptoms and pathogen/insect.

Plant Disease
Agastache (Giant Hyssop) Rust
Alder Alder Leaf Curl
Ascochyta Leaf Spot
Sooty Mold
Alfalfa Leptosphaerulina Leaf Spot
Alyssum High EC, Low pH
Amaryllis Leaf Blotch
Amelanchier Anthracnose
Powdery Mildew
Apple Apple Scab
Cedar-Hawthorn Rust
Crown Gall
Japanese Apple Rust
Nectria Canker
Sooty Blotch
Winter Injury
Arborvitae (Thuja) Arborvitae Leaf Miner
Didymascella Leaf Blight
Pestalotiopsis Blight
Phyllosticta (associated with leaf blight)
Ash Anthracnose
Ash Rust
Flower Gall
Astilbe Discosia
Powdery Mildew
Azalea Leaf Gall
Powdery Mildew
Bacopa Botrytis Canker
Basil Downy Mildew
Bay (Laurel) Anthracnose
Bean POTY Virus
Uromyces Rust
Fusarium Rot
Beech Sooty Mold
Birch Gloeosporium
Marssonina Leaf Spot
Powdery Mildew
Blueberry Colletotrichum
Leaf Rust
Phomopsis Canker and Tip Blight
Witches’ Broom
Bouncing Bet Alternaria Leaf Spot
Boxwood Boxwood Leaf Miner
Volutella Blight
Brambles Orange Rust
Buckthorn Crown Rust
Bugbane Ascochyta Leaf Spot
Cabbage Black Rot
Calendula Fusarium Wilt
Calibrachoa Black Root Rot
Calibrachoa Mottle Virus
Tobacco Mosaic Virus
Carrot Alternaria Leaf Blight
Celery Alternaria Blight
Chard Cercospora Leaf Spot
Cimicifuga Ascochyta Leaf Spot
Cissus Powdery Mildew
Clematis Leaf Spot
Coleus Downy Mildew
Corn Common Smut
Alternaria Leaf Blight
Corylus Eastern Filbert Blight
Cosmos White Smut
Crucifers Club Root
Cucurbits Alternaria Leaf Spot
Bacterial Wilt
Belly Rot
Black Rot
Fusarium rot
Gummy Stem Blight
Phytophthora Fruit Rot
Powdery Mildew
Septoria Leaf Spot
Rodent Damage Response
Unidentified Phytotoxicity
Daphne Tubercularia
Daylily Aureobasidium
Leaf Streak
Delphinium Phoma
Dogwood Dogwood Anthracnose
Golden Canker
Powdery Mildew 1
Powdery Mildew 2
Septoria Leaf Spot
Douglas Fir Rhabdocline Needle Cast
Swiss Needle Cast
Elder Leaf Spot
Elm Dutch Elm Disease
Phomopsis (secondary?)
Euonymus Crown Gall
Fig Rust
Fir Broom Rust
Fir-Fern Rust
Phyllosticta Needle Blight 1
Phyllosticta Needle Blight 2
Rhizosphaera Needle Cast
Fothergilla Botrytis
Fuchsia Insecticidal Soap Damage
Garlic Embellisia Bulb Canker
Garlic Bloat
Mushy Rot
POTY Virus Positive
White Rot 1
White Rot 2
Geranium Bacterial Blight
Botrytis Leaf Spot
Pelargonium Flower Break Virus
Pythium Root Rot
Yellow Net Vein Virus
Gladiolus White Rot
Grape Black Rot
Downy Mildew
Hawthorn Entomosporium
Phomopsis Canker
Hazelnut Eastern Filbert Blight
Hemlock Hemlock Rust
Hemlock Tip Blight
Heuchera Rust
Hickory Ascochyta
Powdery Mildew
Holly Glyphosate Injury
Hollyhocks Rust
Honeysuckle Leaf Blight
Powdery Mildew
Hops Downy Mildew
Horsechestnut Guignardia Blotch
Hosta Alternaria Leaf Spot
Botrytis Leaf Spot
Crown Rot
Hosta Virus X
Hydrangea Ascochyta
Gray Mold
Impatiens, Garden Alternaria Leaf Spot
Downy Mildew
Impatiens, New Guinea Myrothecium Leaf Spot
Ipomoea Oedema
Iris Leaf Spot
Rhizome Rot
Jack-in-the-pulpit Rust
Jostaberry White Pine Blister Rust
Juniper Gymnosporangium Rust
Kabatina Blight 1
Kabatina Blight 2
Leptosphaeria (secondary?)
Mytilinidion (secondary)
Oidiodendron (secondary)
Ojibwaya perpulchra (secondary)
Phomopsis Twig Blight
Tip Blight
Kale Leptosphaerulina Leaf Blight
Lamium Downy Mildew
Lemon Anthracnose
Lettuce Downy Mildew
Leaf Spot
Lilac Anthracnose
Ascochyta Blight
Leaf Spot
Lily Botrytis Blight
Poor bulb storage
Mallow Rust
Maple Anthracnose 1
Anthracnose 2
Cristulariella Leaf Spot
Leaf Blister
Stegonsporium Canker
Tar Spot
Mayapple Rust
Mountain Ash Entomosporium Leaf Spot
Mountain Laurel Phytophthora Leaf Spot
Myrtle Black Root Rot
Ninebark Powdery Mildew 1
Powdery Mildew 2
Oak Anthracnose
Leaf Blister
Tubakia Leaf Spot
Botryosphaeria Canker
Oak Leaf Gall
Oat Crown Rust
Onion Purple Blotch
Storage Rot
Orchid Dendrobium Anthracnose
Miltonia Anthracnose
Oncidium Anthracnose
Pachysandra Volutella Blight
Pansy Black Root Rot
Parsley Septoria Leaf Spot
Pea Ascochyta Leaf and Pod Spot
Black Root Rot
Mycosphaerella Blight
Powdery Mildew
Pear Fabraea Leaf Spot
Pear Scab
Peony Anthracnose
Cercospora Leaf Spot
Leaf Blotch
Peony Ringspot Virus
Pepper Anthracnose
Fruit Rot
Thrips Damage
Petunia Low pH; High Soluble Salt
Phlox Downy Mildew
Powdery Mildew
Septoria Leaf Spot
Pieris Pestalotiopsis Leaf Spot
Pine Bifusella Needle Blight
Coleosporium Needle Rust
Davisomycella Needle Blight
Lophodermium Needle Blight
Ploioderma Needle Cast
Salt damage
Sarea resinae (Secondary?)
Sphaeropsis (Diplodia) Blight
Stagonospora (Secondary?)
Truncatella Needle Blight
White Pine Blister Rust
Poppy Alternaria Leaf Spot
Anthracnose Rot 1
Anthracnose Rot 2
Potato Alternaria Leaf Spot
Chimeric Variegation
Common Scab
Fusarium Tuber Rot
Growth Cracks
Herbicide Damage
Late Blight
Potato Virus Y
Privet Thedgonia Leafspot
Quince Rust
Raspberry Anthracnose
Raspberry Cane Maggot
Orange Rust
Rhododendron Gray Leaf Blight
Rose Black Spot
Rose Midge
Rosemary Botrytis
Powdery Mildew
Rudbeckia Downy Mildew
Rye Ergot
Schlumbergera Oedema
Shepherd’s Purse Downy Mildew
Soybean Downy Mildew
Spinach Cladosporium Leaf Spot 1
Cladosporium Leaf Spot 2
Downy Mildew
Spruce Frost Injury
Herbicide Injury
Rhizosphaera Needle Cast
Sirococcus Blight
Spruce Needle Rust
Stigmina infection
Weir’s Cushion Rust
Squash Black Rot
Stone Fruit (Prunus) Black Knot
Blumeriella Leaf Spot
Brown Rot
Cherry Leaf Spot
Peach Leaf Curl
Peach Scab
Peach Botrytis
Powdery Mildew
Strawberry Botrytis Rot
Strawberry Leaf Spot
Sunflower Septoria Leaf Spot
Sweet Potato Oedema
Sweetbay Magnolia Anthracnose
Tomato Alternaria Stem Canker
Blossom End Rot
Chimeric Variegation
Cristulariella Leaf Spot
Early Blight
Late Blight
Leaf Mold
Magnesium Deficiency
Septoria Leaf Spot
Stemphylium Leaf Spot
Thrips Damage
White Mold
Tulip Botrytis Bulb Rot
Turf Anthracnose
Crown Rust
Red Thread
Slime Mold
Veronica Phoma Rot
Vinca Phoma Stem Rot
Violet Rust
Wheat Leaf Rust
Loose Smut
Powdery Mildew
Tan Spot
Witchhazel Blight
Wild Ginger Black Root Rot
Zinnia Alternaria Leaf Spot