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. |
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| 107 Images of 42 Subjects | View Subject List | View Image Details | View Thumbnails |
| Image | Subject Name | Scientific Name | Description |
|---|---|---|---|
| 5062040 | decay | Cross-section of the pore layer of the fruiting body of a wood decay fungus. | |
| 1377034 | bloodroot | Sanguinaria canadensis | Roots showing characteristics which gives this plant its common name "bloodroot" |
| 5300075 | red pine | Pinus resinosa | Pole-sized red pine stand |
| 5046019 | red pine | Pinus resinosa | A typical horizontal branch in red pine |
| 5035076 | Armillaria root rots | Armillaria spp. | Block of resin from base of tree infected by Armillaria |
| 5054008 | fall color | Fall color in sugar maple, Michigan Upper Peninsula | |
| 5038082 | green ash | Fraxinus pennsylvanica | Helathy open-grown green ash |
| 5045012 | bur oak | Quercus macrocarpa | Large horizontal branch development in bur oak |
| 5252016 | shelterwood | Residual white pine in a shelterwood regeneration cut. | |
| 5252017 | shelterwood | Dead white pine and aspen retained in a shelterwood regeneration cut. | |
| 5252018 | shelterwood | Live and dead white pine retained in a shelterwood regeneration cut. | |
| 5044036 | branch union | Strong branch unions in Tilia cordata | |
| 5044050 | unpaved roads and trails | A forest road, in fall. | |
| 5044051 | frost and winter injury (general) | Oak leaves coated with hoarfrost in winter. | |
| 5053044 | included bark | Ash tree with moderate amount of included bark and some sap flow at the junction of branch and stem. | |
| 5050075 | deadwood and snags | Large dead branch in upper crown. | |
| 5050076 | deadwood and snags | Dead branch in upper crown. | |
| 5050077 | deadwood and snags | Broken, dead branch. | |
| 5048039 | included bark | Major crack caused by upright, codominant branching and included bark. | |
| 5048040 | branch union | Strong, U-shaped branch union in sugar maple. | |
| 5048042 | included bark | Codominant branch failure and bark ripping caused by included bark. | |
| 5048081 | beech bark disease | Nectria coccinea | Rough bark on American beech, which serves as a location for Cryptococcus fagisuga to become established. |
| 5034048 | poor architecture | Example of a branch crook | |
| 5034079 | clubmoss | Lycopodium spp. | Sporophylls of a Lycopodium sp. |
| 5034080 | clubmoss | Lycopodium spp. | Sporophylls of a Lycopodium sp. |
| 5034081 | clubmoss | Lycopodium spp. | Lycopodium sporophylls |
| 1301016 | snow and ice damage (snow load) | Ice | |
| 5052079 | branch union | This image illustrates good, U-shaped branch angles of attachment. | |
| 5038024 | dynamic tree support | Cobra cable system | |
| 5037069 | dynamic tree support | "Cobra" system cabling on a large American elm. | |
| 5043092 | pruning (general) | proper pruning cuts may completely close over time | |
| 5043006 | tree anatomy | branch collar | |
| 5043007 | tree anatomy | Branch collar and branch bark ridge | |
| 5052089 | topping | ||
| 5052055 | imbedded objects | golf ball imbedded into tree. | |
| 1397107 | exposed roots | exposed roots damaged by mowers | |
| 5032071 | poor architecture | ||
| 5032093 | Armillaria root rots | Armillaria spp. | Mycelial mats and resin production at the root collar of a declining spruce in Wisconsin. |
| 5032094 | white ash | Fraxinus americana | winter buds |
| 5047086 | Armillaria root rots | Armillaria spp. | rhizomorphs |
| 5047087 | Armillaria root rots | Armillaria spp. | rhizomorphs |
| 5027071 | poor architecture | ||
| 5029055 | frost and winter injury (general) | frosted branch; Hoarfrost on spruce needles. | |
| 5028022 | cane fruit (blackberry, raspberry) | Rubus spp. | thorns and flowers |
| 5028023 | cane fruit (blackberry, raspberry) | Rubus spp. | thorns and flowers |
| 5027039 | acorn jay | Garrulus glandarius | cache created by the acorn jay |
| 1397101 | included bark | weak union | |
| 1397043 | poor architecture | poor architecture combined with decay | |
| 1397100 | tree anatomy | Bur oak with strong, u-shaped crotch | |
| 1397109 | pruning (general) | Good pruning cut on bur oak | |
| 1397111 | pruning (general) | good pruning cut; good callus growth | |
| 1397112 | pruning (general) | Painted pruning wounds on white spruce. Painting pruning wounds is not a recommended procedure, except under very special circumstances, to prevent spread of disease. | |
| 1397115 | pruning (general) | Proper pruning cut on small branch. | |
| 1397119 | pruning (general) | Proper placement of saw for pruning cut | |
| 1397120 | pruning (general) | good pruning cut | |
| 1397123 | topping | poor pruning practice: topped tree | |
| 1397134 | tree anatomy | dead branch delimiting the edge of the branch collar | |
| 1397136 | pruning (general) | proper cut | |
| 1397102 | tree anatomy | tree with fair u-shaped crotch | |
| 1397103 | tree anatomy | Red maple with stable, u-shaped crotch | |
| 5047021 | white spruce | Picea glauca | needle wax plugs |
| 5061013 | Douglas-fir | Pseudotsuga menziesii | very large stump |
| 5031097 | artist's conk | Ganoderma applanatum | snails on artist's conk |
| 5036025 | spruce budworm | Choristoneura fumiferana | feeding budworm |
| 5056030 | Neonectria canker | Neonectria galligena | asci |
| 5055014 | larch needle cast | Hypodermella laricis | needle reflush |
| 5049077 | periodical cicada | Magicicada spp. | emerging cicada |
| 5044062 | pruning (general) | good pruning cut and callus | |
| 5044063 | pruning (general) | good pruning cut; fresh | |
| 5044064 | pruning (general) | good pruning cut; small | |
| 5044065 | pruning (general) | good pruning cuts | |
| 5044066 | pruning (general) | good pruning cuts | |
| 5044067 | pruning (general) | good pruning wound | |
| 5043002 | imbedded objects | tree bound with rope at crotch | |
| 5043050 | imbedded objects | cable around tree | |
| 5049088 | northern tooth | Climacodon septentrionalis | underside of fruiting body |
| 5050067 | thick-walled maze polypore | Daedalea quercina | underside |
| 5051070 | periodical cicada | Magicicada spp. | emerging cicada |
| 5043058 | cedar-apple rust | Gymnosporangium juniperi-virginianae | close up of fruiting body |
| 5043060 | cedar-apple rust | Gymnosporangium juniperi-virginianae | close up of spore tubes |
| 5043063 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043064 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043065 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043066 | cedar-apple rust | Gymnosporangium juniperi-virginianae | |
| 5043067 | cedar-apple rust | Gymnosporangium juniperi-virginianae | |
| 5043068 | cedar-apple rust | Gymnosporangium juniperi-virginianae | |
| 5043069 | cedar-apple rust | Gymnosporangium juniperi-virginianae | |
| 5043070 | cedar-apple rust | Gymnosporangium juniperi-virginianae | |
| 5043071 | cedar-apple rust | Gymnosporangium juniperi-virginianae | |
| 5043072 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043073 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043074 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043075 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043076 | cedar-apple rust | Gymnosporangium juniperi-virginianae | |
| 5043077 | cedar-apple rust | Gymnosporangium juniperi-virginianae | |
| 5043078 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043079 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043080 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5043081 | cedar-apple rust | Gymnosporangium juniperi-virginianae | telia |
| 5038013 | oak wilt | Ceratocystis fagacearum | Chalara anamorph |
| 5033018 | American beaver | Castor canadensis | dam |
| 1301064 | thick-walled maze polypore | Daedalea quercina | Occurs on oaks, causing a brown rot. |
| 1301002 | Chlorociboria fungus | Chlorociboria aeruginosa | Smal cap fungus that grows on dead wood |
| 1301003 | sulfur shelf | Laetiporus sulphureus | The sulphur shelf fungus is a common cause of heartrot of oaks in the U.S. This is an unusual form for this fungus. This sporocarp was fruiting on the top surface of an oak stump. The fungus usually forms overlapping shelves on vertical surfaces of the tree. |
| 1301032 | clinker polypore | Inonotus obliquus | Sterile conk (no spores are produced) |
| 1301035 | cherry scallop shell moth | Rheumaptera prunivorata | |
| 1301036 | cherry scallop shell moth | Rheumaptera prunivorata |
