palmBob on Dave's Garden has a write up on Echeverias. I don't grow these, don't generally see anything like them, but would imagine your yellow flowered plant is one of them. Check out the link. Daves Garden is a member supported site where you have to pay to belong but you can access some stuff like this article without being a member. If I recall correctly, palmBob is a veterinarian, but generally has good advice and writes well researched articles.
