Sounds odd, but it was constructed of different types of wood. The flowers at the base were wood as well

I've never seen the trunk dressed like this!

Next to the Rose Garden

Beautiful fake tree trunks called Faux Bois (false wood in French). It is an age-old art form that uses steel and concrete to create a structure that looks deceptively like rustic wood. Traditionally in the craft, wood textures are freehand sculpted into the final wet layer of a medium such as mortar or grout. There are no molds or stamps, no casts of real trees or wood.

Originally created in 1915, they were restored, starting in 2010, by my friends uncle Terry Eagan. More info here: http://www.fauxboisconcrete.info/