In The Garden: Mysterious tree/shrub with thorns

We live at the south end of Puget Sound. We have had growing for the past two years a mysterious deciduous tree/shrub in our flower garden. We would like to transplant it, but need to know what it is and its planting criteria. We would guess it might be a member of the quercus family. At the present time it is about 1.5 meters tall, with smooth brown trunk turning to red as the branches get smaller. It has alternating pinnate leaves, the largest one of which is about 4 cm long. It looks similar to a white oak leaf but is a little more angular. At the intersection of most leaves with the branch there is a very sharp thorn, about 1 cm in length, perpendicular to the branch.
Thanks for the help

 

Sounds a lot like a Crataegus (Hawthorn) of some kind.

 

Thanks for the quick response.
Does look from the leaf that it might be a Hawthorn (Crataegus curvisepala). this is a tough one to look up on the web because most of the sites are selling its medicinal properties. To our knowledge, though (we get out of the NW rain most of the first quarter) there are neither flowers nor fruit....or at least not when we are around. Do you know whether there are varieties of Hawthorn with neither? I also saw one picture of a blackthorn leaf that looks identical, but this is not a dark colored shrub.

 

All will flower and fruit -- if conditions are right.

The common hawthorn locally, which can be a bit of an occasional invader, is Crataegus monogyna.

 

Thank you. will pass on to our gardener (my wife, that is!)

 

Many Pacific Northwest sites are infested with numbers of common hawthorn trees. Jacobson, Wild Plants of Greater Seattle - Second Edition (2008) notes that the species is "very coimmon" here, and actually far more abundant in the Seattle area than the native black hawthorn species.

 

thanks. will check out the book.