Arborvitae (tree of life) begins just left of Great Tree Route; look for two bolts near the ground, and additional bolts higher up. Though it doesn't look remarkable, it offers fine climbing at an even grade (several 5.10 cruxes), with good rock.
Pitch 1, 5.10: Pull through a small, bolt-protected overhang and continue to a steep groove. An awkward 5.10 crux (two bolts) is followed by an easy section that gains the right side of a headwall. Breach the headwall at an overhanging flake, clip a bolt, and perform crux moves to rock onto a slab. Traverse left beneath the final bolt, and then go more or less straight up a pleasant slab to a belay ledge with chains.
Both cruxes on this pitch are devious: probably on the easy side of 5.10 for tall people, and harder for short folks.
Pitch 2, 5.10b: Traverse right on the belay ledge for 15 feet, find a good cam placement (extra long sling), and then climb up to a bolt. The remainder of the pitch follows thin cracks to a nice ledge, on which grows a big pine tree (same belay spot as Great Tree Route). The crux layback comes at the end of the pitch.
One can avoid the layback section by stepping left to the crack finish on Nosebleed (also 5.10).
Poison ivy grows on the hillside at the base of this route. We stacked some rocks to bury an ivy patch; this provides a good spot for the rope bag. A water streak runs down portions of the route -- expect some moisture after rains. In the winter, if there's melting snow on the hillside above the cliff, this route is probably dripping.
Location
If you have my guidebook, this would be route #14.5, between Great Tree Route and Red Tag. It's very easy to find without the guide: walk to the left side of December Wall, and locate the biggest pine tree growing on the cliff, about 140 feet above the ground. This route climbs directly to the tree.
Descent: there are slings around the big tree (they could stand to be replaced as of this writing). Rappel 140 feet to the ground, or rappel 50 feet and swing left to the chains atop pitch 1. A 90-foot rappel reaches the ground from here. Your rope will fall onto the rocks stacked at the base of the route, but also onto the poison ivy, unless you take great care to catch it all as it falls.
If you want to climb the route, but don't want to risk having your rope fall into poison ivy, climb an easy third pitch to the top of the wall, and walk off left.
Protection
There are 6 bolts on the first pitch, and one on the second; the rest requires gear. Bring wires and all cams to a #1 Camalot. A medium RP is useful for the upper slab on pitch 1 (it can be backed up with a shallow wire; I placed both); this placement is easy to miss (short, tiny crack about 12 feet above and left of the last bolt). On pitch 2, stretch left to a horizontal crack to find your first protection above the lone bolt on that pitch. Small cams are needed for the second pitch crux (#0.1 and #0.2 Camalots were used on the FA).