Willow is named for the tree known for bending in strong wind without breaking, and the name is traditionally associated with flexibility rather than rigid strength. It's often read as suggesting a graceful kind of resilience -- adaptability treated as a genuine strength, not a compromise or a lesser form of endurance.
Venus is opposite to Mercury. He comprehends languages and discipline; she delights and pleasures, Jupiter the like to Mars; this coveteth mercy and justice; that, impiety and cruelty. - William Lilly (1602.-1681.)