Each June I always notice a white, fluffy material floating through the air. I assume it comes from a plant. What is it?
This material, which can be present in copious amounts, is from eastern cottonwood trees. One of the largest eastern hardwoods, the cottonwood is fast-growing but short-lived. The wood is soft, and because of this, the trees do not hold up very well under storm conditions.
Eastern cottonwood trees are very common in Northern New York and the species has separate male and female trees. The fluffy material that is disseminated in late spring contains seeds and is the fruit of female cottonwood trees, thus the name. Depending on the location, seed dispersal can take place over several weeks. With heavy dispersals, the ground underneath cottonwoods can appear to be snow-covered.
The cottony material floats easily through the air, aiding in the dispersal of the embedded seeds. If the trees are near water, the shorelines can become covered with the seed material; water aids seed dispersal also.
Eastern cottonwoods tend to flower when they are young (five to 10 years), compared to other hardwood trees. Over a life span of about 70 years that is an impressive period of seed output. The seeds are annoying for a short period of time, but we should marvel at the strategies this species uses to reproduce.
Over the past few years, I have noticed an abundance of yellow flowers along roadways and in old fields. They appear in early summer and look like a yellow version of Queen Anne’s lace. Someone told me they are toxic — is this true?
The plant you are referring to is called wild parsnip. Over the past 10 years, populations of this perennial plant have exploded. They can grow to 6 feet in height and the yellow flowers that develop in summer are quite attractive. But do not touch this plant. You are correct — it is poisonous. Contact with the plant sap can cause severe burns and rashes. In people who are allergic to it, this rash is much more severe than a typical poison ivy rash.
If you have a few plants on your property, they can be easily controlled by cutting. After that, keep the area mowed to prevent new plants from developing. For larger populations or for plants that are in areas that cannot be easily cut, herbicidal controls are the best option. Do not mow or use a weed trimmer on large populations. This will cause the plant sap to come in contact with your skin more readily.
If you have to go near the plants, cover yourself completely and wear gloves if you must handle the plants. Applications of herbicides should be done before the plants flower. If you wait until flowering has begun, the plants may produce a seed crop that will lead to more plants next season. Seeds that develop can remain viable for up to four years.
Questions answered by Sue Gwise, consumer horticulture educator, Cornell Cooperative Extension Association of Jefferson County.