I spotted this low (for now) ground cover growing on the North side of my wood picket fence. I'm having a hard time determining if it is the invasive Armenian blackberry (Rubus armeniacus) or the native R. ursinus. I'm leaning toward R. armeniacus, but have a slight reason to hope it is R. ursinus. I've had occasional R. armeniacus in my yard before, and have removed them right away, preventing them from taking hold. This new plant has been growing for about 3-6 months and has not yet flowered. The location is just a few hundred feet above sea level, on the East side of the Cascades. The plant I see now has three leaflets, but it looks like some of these are starting to split into five leaflets. It is growing low to the ground, so far. When I compare to pictures I see on the internet, the general appearance of the surface of the leaves resembles R. armeniacus more than R. ursinus. Please take a look at my photos and let me know if you can determine which plant this is. If it is R. ursinus, I would appreciate any tips for managing their growth and fruit productivity in my yard. Thank you.