This is the compact "Power Flower" block (sometimes called a Power Flower Bonsai Pot) from the Minecraft Mods "Project EX" and "Project Expansion". These are miniature versions of structures that the mod ProjectE encourages you to build.

I have included the original export (from the Minecraft files) in addition to a remodeled version with proper UV mapped textures and a watertight mesh. I have included all colors / tiers of the power flowers as alternate materials, so you can easily choose which one you want!