This hybrid of H. 'Sum and Substance' × H. pycnophylla was originated by Dr. Kevin Vaughn of Massachusetts and registered on his behalf by Kevin Walek (Hosta Registrar) in 2009. This large size mound with upright foliage grows to about 26 inches in height and 58 inches wide. The leaves are broadly ovate, moderately corrugated, moderately cupped upward and downward with thick substance. Very pale lavender flowers bloom on short scapes in August. It sets viable seeds in blue-green colored pods.

According to The Hostapedia by Mark Zilis (2009), "...is a throwback to its H. pycnophylla pollen parent and develops scapes that lie within the foliage and are ornamentally insignificant."

Similar species include H. nigrescens.

According to the 2019 AHS Online Auction webpage, "H. 'Nancy Gill' is a seedling from H. 'Sum and Substance' x H. pycnophylla. Hybridizing with S&S is difficult because S &S is a triploid (3-3-3) and H. pycnophylla is diploid. Successfully crossing a triploid with a diploid is usually very iffy.

H. 'Nancy Gill' was flow cytometric measured and found to be "almost triploid." It's an "aneuploid"; ploidy is 2.7-2.7-2.7 or 2.8-2.8-2.8. Nevertheless, 'Nancy Gill' acts like triploid S&S. Most likely 'Crickett's Mouintain Mist' has the same ploidy and acts similarly."