pictures

This is one of the only semi-useful images I can find:

http://edis.ifas.ufl.edu/LyraEDISServlet?command=getImageDetail&image_ soid=FIGURE 1&document_soid=EP453&document_version=1

One does a little better with Magnolia campbellii, a tree which truly demands a maritime/subtropical highland climate:
http://apps.kew.org/trees/?page_id=111 Is it just that there are only a handful of Gresham trees to have had time to get that big? Maybe his originals were lost?

If the original tree still exists, and is well developed. For instance, last year I went to see the original 'SHN' dove tree. It turned out to be small and bushy. If any clones have been put on seedling rootstocks of normal vigor it seems these combinations may soon grow larger than the mother plant. I am growing one myself, but I don't know if it is a graft or a cutting.

Thank you for being so clear and easily understandable!

Next please.

Given your example, there are not all that many named forms of Sequoia sempervirens whereas there are literally dozens of magnolia species, umpteen hybrids and countless numbers of named cultivars - photos of mature specimens of all would be overwhelming. As with the case with many flowering plants, even genus monographs/speciality books limit the bulk of their illustrations to flowers.

Since Gresham was a California-based hybridizer, you might want to check out the Los Angeles County Arboretum in Arcadia, which has one of the largest coillections of deciduous magnolias in the country - sure to have some of his. You might want to check out Gossler Farms in Oregon as well - a huge supplier of magnolias.