Hoya flowers are normaly borne in umbels with many individual flowers. Flower numbers depend on the age of plant, vigor, environmental conditions and of course genetics. Some umbels are tight with individual flowers in short pedicels. Most of this type produce perfect spherically shaped umbels, that are really beautiful and distinctly attractive.
Some hoyas however produce flowers in longer pedicels, with flowers like sprays. Sometimes the pedicels are also of different lengths and the individual flowers have staggered maturities. Most of the species i will show below are of this 2nd type of flowers, scattered and not the spherical umbels. Only the last one belongs to the 1st umbel type. They are all mildly and pleasantly scented. The first two are growing upright like a bush, while the last two are twining vines.