My s. rubra ssp. wherryi are as tall as 15". My s. rubra wherryi "Giant form" gets to 24", and the s. rubra ssp. wherryi "Chatom Giant have been known to reach 30" though 26- 28" seem to be the usual. Wherryi is one of those that can really fool you sometimes. Some year it will blow up in your face, and produce 15-18" pitchers. Then shrink down to 12" to 15". I have no idea why it occasionally does this.