Examples are shown for (A) two (Hopf link), (B) three (trefoil knot), (C) four (Solomon's knot) and (D) five (cinquefoil knot) twists. (sciencedaily.com)
Dainty cinquefoil flowers (edible) and showy spirea shrubs (not edible, as far as I know) are also in the rose family. (healthygreenkitchen.com)
University of Pittsburgh biologists Matthew Koski and Tia - Lynn Ashman recently looked at 34 different populations of silverweed cinquefoil, a widespread plant native in temperate zones on both sides of the equator, and found that its flowers were darker near the tropics. (scientificamerican.com)