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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

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!

Need help with plant identification, visit the plant identification page.

 
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Thursday - August 07, 2008

From: Philadelphia, PA
Region: Mid-Atlantic
Topic: Shrubs
Title: Identification of shrub with thorns
Answered by: Nan Hampton

QUESTION:

I have a plant in my garden that I need to identify. It is a tall shrub (approx. 10 feet) that has very large thorns on its green branches. It is now showing small white flowers. I don't know if it looses its leaves (groups of 3 leaves together) over the winter as this is a new property for me. The thorns on this plant are approx. 1-2 inches long and cover the entire plant. Any ideas what this might be? I've never seen anything like it. A neighbor told me she thought it was called "Crown of Thorns" or that it might be something in the orange fruit family. Please help!

ANSWER:

Euphorbia milii (crown-of-thorns) is a native of Madagascar and does have lots of thorns on its stems but it only grows to about 3 feet high. Also, I doubt it would survive Pennsylvania winters since it is hardy to USDA Hardiness Zones 8 to 11 and Pennsylvania Hardiness Zones are mainly 5 and 6.

Here are possibilities for native Pennsylvania shrubs with thorns:

Crataegus phaenopyrum (Washinton hawthorn) 

Crataegus flava (yellowleaf howthorne) 

If none of these happens to be your shrub, please send us photos and we will do our best to identify it.  Please take photos of the whole plant and closeups of the thorns and of the leaves.  Visit the Ask Mr. Smarty Plants page to read instructions (under "Plant Identification" for submitting photos. 

 

 

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