Specimen record
Boneset
Eupatorium perfoliatum
Description
A distinctive wetland wildflower easily identified by its opposite leaves that are fused at the base, so the hairy stem appears to grow directly through them (perfoliate). Flat-topped clusters of dull white flowers bloom in late summer and attract many pollinators. The plant was historically used in folk medicine to treat 'break-bone fever' (dengue) and other ailments, giving it its common name.
Identification tips
- 1Opposite leaves fused at the base so the stem appears to pierce through them (perfoliate)
- 2Flat-topped clusters of dull white fuzzy flowers
- 3Leaves lance-shaped, wrinkled, hairy, with conspicuous venation
- 4Stems stout, hairy, and upright, 60–120 cm tall
- 5Grows in wet meadows, ditches, and streambanks
Specimen & preservation notes
Collect a stem section clearly showing the perfoliate leaf arrangement — this is the key diagnostic feature. Press the flower cluster between extra blotting paper. Label the perfoliate leaf character prominently on the herbarium sheet.
Habitats
Collection calendar
| Wk | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov |
|---|---|---|---|---|---|---|---|---|
| 1 | ||||||||
| 2 | ||||||||
| 3 | ||||||||
| 4 |
Collection notes
Season check
Observed bloom also extends into September.
Flowering records: 195 iNaturalist observations, Massachusetts · Nearby: 236 observations within 25 km