I currently am growing the following magnolias in my yard here in Hamburg NY:

Magnolia X "Butterflies" - bright yellow blooms
Magnolia hypoleuca
Magnolia accuminata
Magnolia tripetala
Magnolia stellata
Magnolia ashei
Magnolia virginiana
Magnolia grandiflora - unknown cultivar grown from seed/Appalachian Nursery
Magnolia grandiflora "Bracken's Brown Beauty"
Magnolia grandiflora "Edith Bogue"
Magnolia grandiflora "Pocano"

I did a lot of online researching on hardy southern magnolias and the finding were intriging and led me to trial the above named cultivars. The one from Appalachian Gardens has been growing in the ground for at least 3 years and is growing well. The named cultivars are all cutting grown, this is important as I tried a Bracken' s Brown Beauty from Carroll Gardens that I found to be grafted. There is no mistaking that as the bottom was not as hardy as the top and died.

From the Landmark Society of WNY website, on Rochester's Highland Park:
"Next on the path are the Magnolias; over 35 species and varieties are located here. The Star Magnolias (Magnolia stellata) begin blooming in late April with the daffodils and early tulips. Saucer Magnolias (Magnolia soulangiana) bloom in May while the Sweetbay Magnolias (Magnolia virginiana) bloom intermittently throughout the season. Other notable magnolias to search out are Magnolia macrophylla (Bigleaf Magnolia) and (Magnolia kobus DC) Kobus Magnolia."

"Thirty-five magnolia species, varieties, or forms are represented in Highland Park, including two endangered species, the Ashe and Fraser magnolias, both native to the southeastern United States. " -- Lilac Festival website (see http://www.lilacfestival.com/2007 Lilac Website/Other Flowers.ht ml)

And from the conifer society:
To the south of the rose family are the magnolias (Magnolia spp.). A New York native, cucumber tree (M. acuminata) grows next to Kobus magnolia (M. kobus), a plant from Hokkaido. Kobus magnolia has white flowers in April and reseeds freely here. Both species have attained timber proportions. The Appalachian native, umbrella magnolia (M. tripetala), grows with hybrid star magnolia (M. stellata) and saucer magnolia (M. x soulangiana), both obtained from a European nursery. At the south end of the magnolias are 14 M. x proctoriana 'Slavin's Showy'. The original chance seedling, which was found in Highland Park, Rochester, is believed to be a cross of Kobus magnolia and anise magnolia (M. salicifolia). In late April, 'Slavin's Showy' displays white flowers 5 inches to 6 inches across."
http://www.conifersociety.org/cs/modules.php?op=modload&name=News&file =article&sid=26&mode=thread&order=0&thold=0&POSTNUKESID=00367fd7d5805e 77a2095890bb9d4068

That's some of the supposedly 35 Highland Park magnolias -- 14 Slavin's Showy Magnolia kobus var. stellata X salicfolia, Kobus magnolia, star magnolia, umbrella magnolia, saucer magnolia, sweetbay magnolia, bigleaf magnolia, and the Fraser and Ashe mentioned above.