I have a rose that had a cluster of buds growing from center of a bloom. Is this very unusual?
Every so often you will get a hickup of nature and get something like what you had. It can also be caused by feeding the roses with a high nitrogen content fertilizer. The rosebush should return to normal blooming status with the next flush of blooms. If not, there may be a genetic problem in that particular cane of the rosebush if such blooms keep coming. Or it may be that high nitrogen fertilizer has been fed for a long period of time and will take some time to wash out of the soils and also the bushes root system. Many of the so called Bloom Buster fertilizers are actually very high in nitrogen content, which over time will increase foliage and eliminate blooming. We have to watch out for those endless marketing gimmicks! :-)