Yellow Jasmine. I had not seen this once-common and familiar flowering vine for many years living well north of its tropical range.
You could easily miss this climbing vine as you race along the interstates of the deep south–until you notice it, and then see it everywhere while it blooms in March and April.
I’ll take the lazy way out and just pass along some botanical background on this lovely–if sometimes noxious–southern wildflower. From Wikipedia…
The nectar is also toxic to honeybees, which may cause brood death when gathered by the bees. The nectar may, however, be beneficial to bumblebees. It has been shown that bees fed on gelsemine have a reduced load of Crithidia bombi in their fecal mater. Reduced parasite load increases foraging efficiency, and pollinators may selectively collect otherwise toxic secondary metabolites as a means of self-medication.
Despite the hazards, this is a popular garden plant in warmer areas, frequently being trained to grow over arbors or to cover walls. Yellow Jessamine is the state flower of South Carolina.