syngoniums:

One of the more subtle indications of unnaturalness in the buyout area lies in what is not there. There are many mature trees, and a chaotic mix of grasses and herbaceous plants, but there are no native understory trees and shrubs. It feels curiously empty at eye level. As one approaches the greenbelt itself, however, there is a sudden reappearance of those plants, including a number of red buckeyes (Aesculus pavia), currently in full bloom.