The photo listed here under Gomphrena serrata is a Gomphrena commonly called "Little Grapes" or “Airy Bachelor Buttons.” I've seen it listed under various species name. It doesn't look like the run-of-the-mill Gomphrena serrata. I truly have no clue which species the "Little Grapes" really is.
The yellow "accents" are the actual flowers. The white parts are just bracts. If the head of bracts is still growing, then the flowers won't be blooming yet. Likewise, if the head of bracts is old then the flowers will have finished blooming and seeds will be developing. I see yellow flowers on your plants.
http://www.wildflower.org/gall...
http://plants.usda.gov/core/pr...
@Horntoad
Jay posted this:
The thread "wildflower galveston island" in
Plant ID forum
