Hypericum perforatum (St. John's Wort): Integrated Pest Management Plan
Crater Lake National Park. 2006. Hypericum perforatum (St. John's Wort): Integrated Pest Management Plan. Crater Lake National Park, OR
Currently, Crater Lake National Park's most prolific and visible exotic plant is Hypericum perforatum (HYPE), also known as "klamathweed" or "St. John's Wort". Back in 1993, HYPE had the highest frequency among all the exotic plants in that year's survey, supplying 32% of all weed patches found. In smaller patches, HYPE can be found in many areas (Munson Valley Road, South Pole Quarry, South Yard, Headquarters area, Mazama Campground, Rim Village). HYPE is most abundant along the highway 62 corridor in patches as small as from one or two plants, to three meter deep yellow-flowered swaths extending for a quarter mile or more. Patches tend to be denser and more abundant closest to the Park boundaries on both Highway 62 South and East, then get progressively more sparse as one continues up road towards Munson Valley Road. The concern with this plant is that established patches are difficult to eradicate, and although efforts have been made over the years to hand-pull individuals, total numbers do not seem to be reducing, and gradually patches threaten to spread and grow tenaciously into new territories. A lot of the concern comes from what we know about the plant's biology.
- Type
- Unpublished Report
- Authors
- Crater Lake National Park
- Date of Issue
- 2006
- Units
- CRLA
- Keywords
- Abundance (Biodiversity), Alien Species, Distribution (Biodiversity), Exotic Species, Hypericum perforatum (Common St Johnswort Common St. John's Wort Common St. Johnswort Klamath Weed Klamathweed St. John's Wort St. Johnswort), Integrated Pest Management (IPM), Invasive Plants, Non-Native Species, Observations, Presence (Biodiversity), Resource Management, Theales, Vascular Plant, Vegetation