The flowers of Hoya species, and Asclepiad flowers in general have undergone massive development from their Apocynaceae counterparts. All names of parts are in bold , and thus all bold words can be matched up with the above diagram. The whole purpose of this extensive modification is to better discriminate between which pollen a plant will be fertilized with. Note that this dramatic development is just one of the ways Hoya reduces cross pollination. The pedicel is the stem to which the flower is attached to the plant.
Peduncles are often persistant and re- bloom numerous times.
If the flower is successfully fertilized the pedicel thickens. The sepals protect the young flower from damage and are really modified leaves. A secondary function may be to protect the young follicle from damage as well. The corolla is a set of modified petals, that have been fused into one continuous structure. The corolla is perhaps the most visible and striking part of the flower and may be brightly colored, glossy, hairy or in some cases minutely scaled.