While living in Japan and practicing flower arrangement, I often used a branch known as ossified broom. It was always available at flower stores there. The color is gray-green, has the typical multiple straight stems as Scotch Broom but also had some thick and twisted branches that are very attractive in arrangements. I would like to plant it so that I would have a ready supply. Can you help me find the correct name?
I consulted a number of books on Japanese flower arrangement, including The Art of Arranging Flowers: A Complete Guide to Japanese Ikebana, by Shozo Sato (Harry N. Abrams, 1965). ‘Broom’ may be the common name of a number of different plants, such as Spanish broom (Spartium junceum), Scotch broom (Cytisus scoparius), and broom cypress (Kochia scoparia). Unfortunately, these plants are considered noxious weeds in the State of Washington.
You may want to consider a type of broom (Genista or Cytisus) that is not considered invasive.
From your description of the branches, I wonder if the appearance would be similar to
Corylus avellana ‘Contorta’ (Henry Lauder’s walking stick).