Native Plants

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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)