Native Plants

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

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Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

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Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

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Wednesday - June 20, 2007

From: buda, TX
Region: Southwest
Topic: Plant Identification, Poisonous Plants, Vines
Title: Recognizing poison ivy
Answered by: Jimmy Mills

QUESTION:

I am having a difficult time identifying poison ivy. It seems so many plants look like poison ivy can you help me I don't want to kill everything but on the same hand I don't want to itch. Thanks for your help.

ANSWER:

"Leaves of three, better let be". This old aphorism is a good start for identifying the noxious weed (Toxicodendron radicans (eastern poison ivy), however the plant can be quite variable in appearance. Technically the "leaves" are leaflets, but they still contain the active principal urushinol that ellicits the allergic reaction in susceptible individuals.

Two plants that are often confused with poison-ivy are Box Elder Acer negundo (boxelder), and Virginia creeper Parthenocissus quinquefolia (Virginia creeper) . Close examination of the plants reveals that though the leaflets in all three plants seem similar, their arrangements are different. The Poison-ivy of course has leaflets arranged in threes; the Box Elder has five to seven leaflets per leaf arranged in a pinnate fashion, however there can be only three leaflets; and the Virginia Creeper has five leaflets per leaf.

This link is provided to let you "know the enemy", and this one offers some care tips if the ememy gets too close.

From the Image Gallery

Eastern poison ivy
Toxicodendron radicans

Box elder
Acer negundo

Virginia creeper
Parthenocissus quinquefolia