By Phran Novelli

PHILADELPHIA (CBS) – There’s plenty of kissing during the holidays, and much of it goes on under mistletoe. Mistletoe has been celebrated in the dead of winter since ancient times, along with other evergreens, because they look lively during the darkest days of the year when most other plants are bare.

READ MORE: Philadelphia To Begin Offering Children Ages 12-15 Pfizer's COVID-19 Vaccine On Thursday After CDC's Recommendation

Christmas mistletoe traditions began in Europe, but the plant grows here in America too. Mistletoe’s a partly parasitic plant – growing into a tree branch to find water and nutrients, but that doesn’t hurt the tree. Here, our native oak mistletoe shows up as green balls hanging like nests way up in bare trees this time of year.

READ MORE: Gasoline Shortage Appears To Be Creeping Into Philadelphia Region As Colonial Pipeline Resumes Operations

Songbirds love the berries, but they’re poisonous to people and pets, so it’s smart to wrap mistletoe in some pretty cellophane to contain the berries before putting it in a holiday display.

MORE NEWS: Man Shot 11 Times, Killed In Southwest Philadelphia Quadruple Shooting, Police Say

Then, remember to stop and smooch your sweetie under the mistletoe – below a tree, out on a winter’s walk or beneath a decoration in a doorway on New Year’s Eve.