"Oh!" Treebeard laughs, shaking himself. "You are hasty, little tiger-druid! But still slow enough to ask wise questions. Let me think...
"Hoom, hoom... It has been long years since Saruman was walking about these woods. He was always polite in those days, and eager to listen, and gave no trouble to his neighbors. He was chosen to be Head of the White Council, in fact - by Master Gandalf and Lady Galadriel and Masters Elrond and Radagast and some others. Though now, I wonder if even then he was not turning to evil ways. Even then, I remember now, he told me very little...
"No, I have never heard of anyone except the gods who can simply see magic. Saruman... He told me little, though I know he could never tell whether a tree was a sleeping Huorn. I saw the Elf-fathers of old once in great doubt over how much of the treasure they had seized was magical - such doubt that they delayed, and they lost the treasure to others, though the most magical jewel had never come into their hands in the first place. A sad story, though I do not regret my own part in it. And if I tell you the whole story, we would be here till the sun sets and rises again."
Treebeard had never liked the Sons of Feanor... and he and his fellow Ents had needed little invitation to make sure they left Ossiriand without the treasure of Doriath that they'd stolen from the Dwarves, and with somewhat fewer Elves than they'd come with.
"As for Saruman's powers... He can control the weather in some ways - I would not be surprised if this dry summer was his doing. He may be able to see at a distance, if he cares to look, and if he were not merely bragging that one time. But his greatest power is his voice. He can make you think he is the wisest friend you have ever had - while he is speaking to you, and for some people perhaps afterwards.
"I do not know if you would be safe from his voice, Tora, since you do not speak any languages he would know from Middle-Earth - but even so, he has stayed in his tower for many a year, so he would likely not risk himself within the range of your teeth."