Joseph O'Brien's Images
Title: Plant PathologistOrganization: USDA Forest Service
Unit: Forest Health Protection
Country: United States
Joe is a plant pathologist with the U.S. Forest Service in St. Paul, Minnesota. in addition to photography, his major interests include tree diseases in forests, woodlands and urban areas, hazard tree identification and mitigation, and mycology. Joe is a graduate of the University of Michigan (B.S. Forestry and M.S. Forest Pathology) and the University of Minnesota (Ph.D. Plant Pathology), and currently works at the Northern Research Station on the University of Minnesota's St. Paul campus. |
| 159 Images of 55 Subjects | View Subject List | View Image Details | View Thumbnails |
| Image | Subject Name | Scientific Name | Description |
|---|---|---|---|
| 1427102 | sudden oak death | Phytophthora ramorum | Bark cracks and bleeding on coast live oak. |
| 1427033 | sudden oak death | Phytophthora ramorum | |
| 1427030 | sudden oak death | Phytophthora ramorum | |
| 1301055 | Eutypella canker | Eutypella parasitica | cobra-head canker |
| 1427053 | sudden oak death | Phytophthora ramorum | Tip symptoms on tanoak seedling, caused by P. ramorum. |
| 5046013 | red oak borer | Enaphalodes rufulus | Attack on bole |
| 5061017 | Fusarium wilts, blights, rots and damping-off | Fusarium spp. | Canker on walnut caused by Fusarium sp. |
| 5061018 | Fusarium wilts, blights, rots and damping-off | Fusarium spp. | Cankiers on the bole of a young walnut, caused by Fusarium sp. |
| 1427018 | sudden oak death | Phytophthora ramorum | Big Sur, California |
| 1301049 | white pine blister rust | Cronartium ribicola | Dead top in eastern white pine caused by white pine blister rust. |
| 1301041 | Phomopsis cankers and twig blights | Phomopsis spp. | |
| 1427017 | sudden oak death | Phytophthora ramorum | Big Sur, California |
| 1427090 | sudden oak death | Phytophthora ramorum | Tanoak dying from P. ramorum infection, Muir Woods State Park, CA. |
| 5061023 | canker | Unidentified canker on young walnut | |
| 5062028 | frost and winter injury (general) | Winter injury in transplanted pine | |
| 5042052 | ash yellows phytoplasma | Candidatus Phytoplasma fraxini | Witches' broom on white ash |
| 5062023 | frost and winter injury (general) | Winter injury to yourn landscape pine | |
| 5062024 | frost and winter injury (general) | Winter injury in recently transplanted pine | |
| 5062027 | frost and winter injury (general) | Winter injury in transplanted pine | |
| 5062029 | frost and winter injury (general) | Winter injury in white pine | |
| 5047034 | basal wound | An ash with an open wound and decay at the ground line | |
| 5062045 | yellow birch decline | Decline symptoms in yellow birch | |
| 1301020 | oak wilt | Ceratocystis fagacearum | Vertical cracks in bark caused by pressure pads. |
| 1198036 | Diplodia blight | Sphaeropsis sapinea | Hail-initiated shoot blight in large trees. |
| 1377020 | Eutypella canker | Eutypella parasitica | Often called "cobra-head canker" because of the characteristic appearance of larger cankers. The trunk often snaps off just above the canker. |
| 5041055 | Diplodia blight | Sphaeropsis sapinea | Dark staining of the wood |
| 5059004 | stalactiform blister rust | Cronartium coleosporioides | Long canker |
| 5059009 | Strumella canker | Urnula craterium | Strumella canker on oak |
| 5059011 | Strumella canker | Urnula craterium | Strumella canker on oak |
| 5059012 | Strumella canker | Urnula craterium | Strumella canker on oak |
| 5059013 | Strumella canker | Urnula craterium | Strumella canker on oak |
| 5054026 | risk tree | Cracks, seams on campground tree | |
| 5045019 | risk tree | A tree with a corrected lean | |
| 5055038 | risk tree | Long crack and decay | |
| 5040068 | oak wilt | Ceratocystis fagacearum | Red oak with oak wilt, shedding leaves and marked for removal |
| 5045085 | Ohia decline | Ohia decline on Hawaii | |
| 5045086 | oak decline | Oak killed by drought, twolined chestnut borer, and Armillaria root rot. | |
| 5045087 | oak decline | Oak tree mortality caused by drought, twolined chestnut borer and Armillaria root rot. | |
| 5053097 | chestnut blight or canker | Cryphonectria parasitica | Chestnut blight canker on American chestnut |
| 5055015 | Eutypella canker | Eutypella parasitica | A very large Eutypella canker in Norway maple, in an urban setting |
| 5055024 | Leucostoma canker of spruce | Leucostoma kunzei | Branch mortality in blue spruce caused by Leucostoma canker |
| 5253099 | Phytophthora root and crown rots | Phytophthora spp. | Bleeding canker on oak |
| 5039072 | oak wilt | Ceratocystis fagacearum | Oak mortality caused by oak wilt. |
| 5039082 | oak wilt | Ceratocystis fagacearum | Small oak tree killed by oak wilt |
| 5051042 | Diplodia blight | Sphaeropsis sapinea | Diplodia shoot blight symptoms in a red pine stand following a hail storm. |
| 5051043 | Diplodia blight | Sphaeropsis sapinea | Symptoms of Diplodia shoot blight in young red pine. |
| 5051056 | transplant shock | Transplant shock (drought symptoms) in an urban tree. | |
| 5044029 | sudden oak death | Phytophthora ramorum | Tanoak killed by P. ramorum. |
| 5052056 | decay | Tree with green crown, but extensive decay in the bole. | |
| 5052057 | decay | Tree with a green crown, but extensive decay in the bole. | |
| 5052058 | decay | Tree with a green crown, but extensive decay in the bole. | |
| 5052059 | decay | Tree with green crown, but extensive decay in the bole. | |
| 5052060 | decay | Tree with green crown, but extensive decay in the bole. | |
| 5052062 | decay | Tree with green crown, but extensive decay in the bole. | |
| 5052063 | decay | Tree with green crown, but extensive decay in the bole. | |
| 5038074 | oak wilt | Ceratocystis fagacearum | Oak wilt crown symptoms. |
| 5044033 | Eutypella canker | Eutypella parasitica | |
| 5034063 | Eutypella canker | Eutypella parasitica | A large Eutypella canker on Norway maple. |
| 5298031 | poor architecture | "Ugly tree" syndrome from multiple defects and decay. | |
| 5298040 | poor architecture | Poor tree architecture caused by accumulated defects, including decay and broken branches. | |
| 5298035 | woodpeckers | Extensive decay and woodpecker damage on dead bole. | |
| 5298042 | decay | Large open cavity and decay in bole of large tree. | |
| 5298047 | decay | Open cavity and decay at base of bole. Peter Bedker, Peggy Sand | |
| 5298058 | decay | Brown cubical rot at base of dead tree. | |
| 5298069 | decay | Tree with wound caused by lightning, and associated woodpecker injury. | |
| 5297081 | sudden oak death | Phytophthora ramorum | Bark cracks with black ooze in coast live oak, a symptom of ramorum canker. |
| 5251049 | sudden oak death | Phytophthora ramorum | Bark discoloration and zone lines in coast live oak. |
| 5251099 | canker | Canker under tarry spot on oak. Cause unknown. | |
| 5048080 | beech bark disease | Nectria coccinea | Beech snap, in a stand affected with beech bark disease. |
| 5048094 | beech bark disease | Nectria coccinea | Beech snap, in a stand affected with beech bark disease. |
| 5050006 | cold injury (low temperature) | White pine terminal bud killed by cold temperature. | |
| 5043094 | sudden oak death | Phytophthora ramorum | Sudden oak death (ramorum canker) symptoms on coast live oak |
| 5034064 | Eutypella canker | Eutypella parasitica | A large canker caused by Eutypella parasitica on a Norway maple in the urban landscape. Sporocarps of Oxyporus populinus, commonly associated with Eutypella cankers, can be seen on the canker face. |
| 5034068 | decay | ||
| 5034083 | decay | Large, dead, decayed white pine. Martin MacKenzie provides scale. | |
| 5032061 | white pine blister rust | Cronartium ribicola | A white pine blister rust canker on a young white pine. |
| 5033100 | Eutypella canker | Eutypella parasitica | A large Eutypella canker on sugar maple. |
| 5032056 | spruce decline | ||
| 5032055 | spruce decline | ||
| 5031065 | spruce decline | ||
| 5037083 | ash yellows phytoplasma | Candidatus Phytoplasma fraxini | |
| 5031053 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Rhizosphaera needle cast on lower branches of white spruce. |
| 5037091 | decay | This is a dead red pine, approximately 30' tall. The hazard is from potential kick-back when people dig at the lower part of the bole. | |
| 5044075 | Scleroderris canker of pine and spruce | Gremmeniella abietina | |
| 5051003 | Diplodia blight | Sphaeropsis sapinea | |
| 5047090 | Armillaria root rots | Armillaria spp. | |
| 5047051 | smooth patch of oak | Aleurodiscus oakesii | Several smooth patch areas on white oak |
| 5031057 | spruce decline | Severe symptoms of spruce decline on the Chequamegon-Nicolet National Forest. The disease is caused by a complex set of factors that result in decline and death of the tree. | |
| 5031042 | annosum root disease | Heterobasidion annosum | |
| 5031043 | annosum root disease | Heterobasidion annosum | |
| 5029041 | Eutypella canker | Eutypella parasitica | "Cobra-head" canker. |
| 5029085 | Hypoxylon canker of aspen | Entoleuca mammata | Canker with cracked bark |
| 5029091 | Hypoxylon canker of aspen | Entoleuca mammata | Canker on young aspen. |
| 5028006 | Diplodia tip blights | Diplodia spp. | Diplodia shoot blight in red pine after a hailstorm. |
| 5028008 | frost and winter injury (general) | with winter frost | |
| 5029013 | Diplodia blight | Sphaeropsis sapinea | Main stem infection causing death of top. |
| 1397087 | decay | Bur oak with decay and large cavity. | |
| 5032025 | oak wilt | Ceratocystis fagacearum | |
| 5032064 | white pine blister rust | Cronartium ribicola | small branch infection |
| 5061027 | white pine blister rust | Cronartium ribicola | |
| 5061032 | white pine blister rust | Cronartium ribicola | |
| 5061052 | white pine blister rust | Cronartium ribicola | |
| 5061053 | white pine blister rust | Cronartium ribicola | |
| 5061070 | white pine blister rust | Cronartium ribicola | |
| 5061071 | white pine blister rust | Cronartium ribicola | |
| 5061077 | white pine blister rust | Cronartium ribicola | rust cankers |
| 5059039 | sycamore anthracnose | Apiognomonia veneta | |
| 5046047 | Sirococcus blight of conifers | Sirococcus conigenus | seedling mortality |
| 5032001 | spruce decline | ||
| 5040095 | Sirococcus blight of conifers | Sirococcus conigenus | droop symptoms |
| 5041039 | sudden oak death | Phytophthora ramorum | bleeding symptom |
| 5041047 | sudden oak death | Phytophthora ramorum | bleeding cracks |
| 5041049 | sudden oak death | Phytophthora ramorum | long drips on trunk |
| 5041059 | Diplodia blight | Sphaeropsis sapinea | canker on main stem |
| 5041074 | Diplodia blight | Sphaeropsis sapinea | severe infection in large tree |
| 5041083 | Diplodia blight | Sphaeropsis sapinea | |
| 5042003 | Diplodia blight | Sphaeropsis sapinea | top kill |
| 5046003 | oak wilt | Ceratocystis fagacearum | tree with close-up of leaves |
| 5057010 | ash heart rot | Perenniporia fraxinophila | |
| 5056016 | Nectria canker | Nectria spp. | |
| 5056017 | Nectria canker | Nectria spp. | |
| 5056019 | Nectria canker | Nectria spp. | |
| 5056024 | Nectria canker | Nectria spp. | |
| 5045074 | oak decline | ||
| 5039064 | oak wilt | Ceratocystis fagacearum | crown symptoms |
| 5051068 | Elytroderma needle cast of pine | Elytroderma deformans | |
| 5053098 | Hypoxylon canker of oak | Biscogniauxia atropunctata atropunctata | |
| 5054002 | Hypoxylon canker of oak | Biscogniauxia atropunctata atropunctata | |
| 5054003 | Hypoxylon canker of oak | Biscogniauxia atropunctata atropunctata | |
| 5055033 | Phytophthora root rot | Phytophthora cinnamomi | |
| 5055034 | Phytophthora root rot | Phytophthora cinnamomi | |
| 5055016 | oak wilt | Ceratocystis fagacearum | |
| 5054029 | white rot | Inonotus glomeratus | |
| 5054053 | iron deficiency | iron chlorosis | |
| 5054057 | iron deficiency | iron chlorosis | |
| 5050008 | comandra blister rust | Cronartium comandrae | |
| 5050010 | comandra blister rust | Cronartium comandrae | |
| 5047075 | black knot | Apiosporina morbosa | |
| 5032044 | Verticillium wilts | Verticillium spp. | |
| 5032045 | Verticillium wilts | Verticillium spp. | |
| 5057057 | white heartwood rot | Phellinus tremulae | |
| 5057032 | false tinder polypore | Phellinus igniarius | |
| 5057036 | robustus conk | Phellinus robustus | |
| 5057056 | white heartwood rot | Phellinus tremulae | |
| 5055041 | needle cast | Lophodermium seditiosum | |
| 5051080 | Eutypella canker | Eutypella parasitica | |
| 5050040 | chestnut blight or canker | Cryphonectria parasitica | |
| 5050062 | Cytospora cankers | Cytospora spp. | |
| 5050063 | Cytospora canker of spruce | Valsa kunzei | |
| 5050064 | Cytospora cankers | Cytospora spp. | |
| 5049042 | brown spot needle blight of pine | Mycosphaerella dearnessii | |
| 5049047 | butternut canker | Sirococcus clavigignenti-juglandacearum | |
| 5049048 | butternut canker | Sirococcus clavigignenti-juglandacearum | |
| 5049050 | butternut canker | Sirococcus clavigignenti-juglandacearum | |
| 5049051 | butternut canker | Sirococcus clavigignenti-juglandacearum | |
| 5049052 | butternut canker | Sirococcus clavigignenti-juglandacearum | |
| 5049069 | chestnut blight or canker | Cryphonectria parasitica | |
| 5049070 | chestnut blight or canker | Cryphonectria parasitica | |
| 5037071 | black knot | Apiosporina morbosa | on main stem |
