Yavanna is the Tolkien character known as the creator of the Two Trees of Valinor.
In Tolkien’s mythology, Yavanna is one of the Valar and is associated with growing things, especially plants and living nature. She creates Telperion and Laurelin, the Silver Tree and the Gold Tree, which illuminate Valinor before the making of the Sun and Moon.
The Trees become central to the history of the First Age. Their light is captured in the Silmarils by Fëanor, and the destruction of the Trees by Ungoliant leads to the exile of the Noldor and the long chain of events behind much of The Silmarillion. Their last surviving light is also connected to later sources of illumination in Middle-earth.
Varda is the Vala associated with stars and heavenly light, so she is sometimes mistakenly named here. Yavanna’s role is specifically tied to the Trees, while the Valar collectively shape and protect the world of Arda.