Anything that's coniferous has to do with trees or shrubs that grow pinecones. If you celebrate Christmas, you might observe the holiday by decorating a coniferous tree with lights and ornaments.
The adjective coniferous is used to describe conifers, woody evergreens that have cones and needles rather than leaves. Coniferous forests and taigas are full of these trees, including pines, hemlocks, junipers, and firs. Whenever you see a pinecone, you can be sure it came from a coniferous tree or shrub. The Latin source of coniferous means "cone-bearing," from roots conus, "cone," and ferre, "to carry."