so earlier today I found a program called PlantStudio which is abandonware from a small studio in 1999. It’s no longer updated, but it runs perfectly fine on modern machines. It allows you to generate flowers! Essentially, you provide a bunch of parameters like number of petals, how the leaves arrange themselves, the shape of the leaves or petals, and other things (you can mess with them later) and generate a pretty flower in 3D. They’re not spectacular renderings, mostly they’re on the level of Google Sketchup- but as you can see, they’re very pretty! You can “randomize” them so they look a little different, and make a boquet of roses, or a bunch of wildflowers, or ivy, or dandelions, whatever you like. When you first open it up, you go “Plant>Create New”, which will walk you through a wizard where you just answer some questions. You can later enter the very detailed specifications for the flower and change them later. Above are examples of what you can do if you just shoop it a little bit :P
You can also go to their website, and download preset plant files, for real-life flowers if you like, and generate some of those. You put all these generated flowers into your main window, arrange/rotate them, and there you go!
It’s free to use, provided you register with the free name/PIN they provide you with.