Here's a reply from an acquaintance Russ which in my dotage I don't understand. Can anyone explain why I'm off the track altogether or has he misinterpreted the q:

Okay, I'll put it another way. A single leaf from each of 4 desert shrubberies is placed in front of me and I am asked to say the name of each.
I would say, "A mesquite leaf, a Mormon tea leaf, a coyote brush leaf, and a creosote leaf." I would not say that a single leaf from a creosote bush was a bush, nor that a single leaf from a mesquite tree was a tree, but I still have to say brush to identify a coyote brush leaf.

If I then made a tea from each type of leaf, I would have mesquite tea, Mormon tea tea (stop giggling!), coyote brush tea, and creosote tea.

If I had a big clump sage plants (genus Salvia), it could be a sage brush (A), but that wouldn't turn it into sagebrush (genus Artemisia) (B). Creosote bush is an example of formation (A), coyote brush is an example of (B).

dalehileman