This flower is huge! It's called King Protea and it's the national flower of South Africa. You can find this flower growing wild in Maui and St. Helena.
There is no other island in the world that is more remote than where this wedding takes place, it doesn't surprise me that this is where they found this flower. St. Helena is located in the South Atlantic Ocean on the Mid-Atlantic Ridge, more than 1,200 miles from the nearest major landmass, in between Rio de Janeiro and Southwestern Africa.
King Protea floral arrangements