In terms of following their mythological archetypes, dryads work very well. But they’re so defined by what they can’t do (move) and how they compensate (charm person) that it can be hard to imagine them as anything but seductresses.
Proud and hot-tempered, the dryad Astrina has always resented her race’s reliance on seduction and stealth. Inspired by her first love—a cosmopolitan dandy whose father made him take fencing lessons—Astrina overcame the usual fey objections to steel in order to learn the rudiments of swordplay. Now an expert duelist after years of practice, she continues to encourage talented men to match blades with her under her oak (though she tree strides away if their attentions stray from martial to marital). Clad in the finest linens, she appears to be the rebellious daughter of a local lordling, and only her dueling pseudonym, “Thorn,” betrays any hint of her true nature.
Nearly hewn in two while defending his forest from rampaging orcs, the old treant Halorrum lay in a healing sleep for so long that an acorn took root in his open wound. The resulting seedling sprouted a dryad, even after its bark merged with Halorrum’s recovering form. The treant awoke to find a dryad bonded to him. He appreciates the company, even if she does chatter on, and she the wisdom and mobility Halorrum offers her that no ordinary oak could match.
The female elves of Shalorn are actually not elves at all, but dryads. Complex rituals similar to those for calling a familiar allow the Shalorn dryads to bond with staffs, spear hafts, or clubs made from living wood. This allows the Shalorn dryads to travel alongside their adventurous elven brothers, and many become powerful druids and rangers in their own right.
—Pathfinder Bestiary 116
Honestly, there’s no reason why dryads couldn’t make a perfectly good player character, once you removed their tree dependency. (This has already been done in John Nephew’s absolutely fantastic PC1 Tall Tales of the Wee Folk and at least one Dragon Magazine article.) You can easily imagine a variation of their tree-bonding ceremony where they separate from their oaks at the cost of their at-will spell-like abilities. (In game terms, this keeps entangle and tree shape from becoming unbalancing; in story terms, a dryad no longer able to shape even a simple block of wood could be a heartbreaking image.)
Speaking of dryads, Wye Oak’s latest album was named the Onion A.V. Club’s top pick of the year. I know, awesome, right?