Mike Masnick wrote basically the post I'd want to about Car Freshner's latest attempt to suppress anyone from using tree-shaped products that smell like trees--you know, descriptive use. I too find the functionality claim interesting and on its face strong, at least to the extent of sharply limiting Car Freshner's rights. The abandonment issue is, I think, stronger from a registration point of view than Masnick seems to--but courts often don't really understand what registration is, or what the specification delineating the claimed matter in the registration is supposed to do in terms of providing notice and matching up to actual use, so it's unpredictable.
Also, I am amazed that perfume for men who want to smell like pine trees exists. (See bottom center, first image.)