Though a ring's endlessly circular shape echoes the eternal, unwavering strength of family bonds, concentric rings symbolize dartboards and oxygen, without which family trees would be finite. Strengthen your family's roots with today's Groupon: for $19, you'll get a side-by-side tree planting from Plant Trees 4 Life, including a pair of tree plantings and a tree-free certificate customized for your honoree (a $35 value).

An Aspen-based organization dedicated to environmental protection, Plant Trees 4 Life regreens habitats by laying down the roots of live-giving trees. Your two saplings, which can honor a loved one, commemorate a special event, or embody your affection for conical vegetation, will help fill out a forest’s embarrassing bald spots, pump out oxygen, anchor its soil, slow down water runoff, and help maintain a lush ecosystem. Though purchasers won't be able to specify their trees' location, they can virtually visit planting sites on Plant Trees 4 Life's website. Currently, the organization is planting its Colorado trees in the Colorado Rocky Mountains.

Providing much-appreciated shade to picnickers and housing baby squirrels, your sustainable tokens of love and gratitude will live on to benefit creatures both large and small. A pair of love trees is the ideal Father's Day gift for an eco-minded patriarch, and serves as a thoughtful present for a highly allergic honey or naturalistic niece.