Here is a photo of a Hoya imperialis corona.  It was taken almost at a 1:1 ratio, but not quite.  I also discovered something new last night – Hoya imperialis blooms do indeed have a scent.  I had put the bloom that I had cut off into a vase in our small bathroom to see how long it would last as a cut flower.  When I went into the bathroom later, I could smell a lightly spicy scent with just a hint of mint, and sure enough it was coming from the flower.  Although my imperialis has bloomed many times before, I had never smelled any fragrance.  I’m wondering if the conditions were not humid enough for it to produce a scent.  Anyhow I now know that it has a very unusual fragrance that is quite lovely.