I was driving through our neighborhood and I saw a lovely small tree absolutely covered with golden blooms. I wondered what kind of tree it was but didn't think more of it until I saw many more when driving up to Princeton. I also saw several on the Princeton University campus. I queried the Garden Web folks and I finally ID'ed it as a spice bush, Lindera Benzoin-confirming it by doing a Google Image search. This is not the same as the Carolina Spice Bush, Calycanthus occidentalis which has larger reddish blooms.
Upon closer inspection the individual flowers on the spice bush are very tiny but appear in clusters. This is one of the earliest shrubs to bloom in Spring only preceded by the witch hazel. I haven't seen very many planted in private home yards but mostly on large campuses, I wonder why? They call it a shrub or bush but to me it looks like a small tree. Apparently there's a butterfly, the spicebush swallowtail (a black butterfly with light blue on the back portions of wings) that eats the leaves and the spice bush also provides food, a berry, for birds in the winter. Some people even use the berries for jams and to spice their food.
I liked the look of the bush so much I bought five. The added bonus of having more swallowtail butterflies cinched the deal. When I took the pictures the trees were slightly past bloom so they don't look as spectacular as a week before.
I was curious about the name benzoin. Sounded similar to the highly volatile aromatic hydrocarbon benzene so I looked it up. Daves Garden website botanary (botanical dictionary) defines it as: "From an Arabic word for aromatic gum".