Joanna, I found two different explanations for this name:
1. Though often seen with two “i”s, the proper spelling of this epithet should have a single “i” as this is the genitive form of Adolphus, the Latinized name for Adolf Engler, who was director of the Berlin-Dahlem Botanical Garden where the type plant of
S. adolphi was growing at the time of its description in 1912. (
http://www.huntington.org/BotanicalDiv/ISI/ISI2014/2014-32.html). Heinrich Gustav Adolf Engler (March 25, 1844 – October 10, 1930) was a German botanist. He is notable for his work on plant taxonomy and phytogeography.
2. named for Adolphe-Théodore Brongniart, 19th century French botanist and scientist (a site called 'Looking at plants').
I believe the first one is the correct version, the reference to the first publication is according to The Plant List:
Notizbl. Bot. Gart. Berlin-Dahlem 5: 277 1912. The accepted name is still spelt with ii.
