This species is a native of the USA, and is easily recognised by its large oak shaped leaves which often turn reddish in the Autumn before they fall.  The flowers are formed in short, broad panicles and are mostly white or cream in colour.  The first cultivars had a 50:50 mix of fertile and sterile florets, but cultivars have now been bred that have densely packed sterile florets forming dense heavy heads that weigh down the thin branches at one extreme, and cultivars with only a sparse covering of sterile florets at the other extreme.  It grows well against a wall where it will use the wall for support and grow up without clinging.