If you have a rash or other skin problem that you think might be plant related, trying using the search engine at the Botanical Dermatology Database. I checked out my family’s old enemy Pastinaca sativa (aka wild parsnip), and learned a few things. First of all, wild parsnip and cultivated parsnip are the same thing, and you can get the blisters and subsequent skin pigmentation from either. Secondly, if your skin is wet (and whose isn’t on a hot summer day?) the reaction is more likely. Third, “the active spectral band for evoking phytophotodermatitis from the plant was found to be 320-360nm.” Okay, so that last part isn’t too helpful, but the other two things were good to know. Eating parsnips poses no problem, but if you like them enough to grow them, wear long sleeves and gloves when you harvest them.
Marcescence is the retention of dead plant organs that normally are shed. It is most obvious in deciduous trees that retain leaves through the winter. Several trees normally have marcescent leaves such as oak (Quercus), beech (Fagus) and hornbeam (Carpinus).
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