For the December-born, the birth flowers are Holly and Narcissus (specifically, the Paperwhite).
According to runtedrun.com, the Holly, which figures abundantly in traditional Christmas decorations, is a symbol of goodwill and is also often used as a name for baby girls born in winter. The meaning of the Holly flower is: the Coming of Joys.
The scientific name is Ilex Aqui folium. The Holly is a shrub with evergreen or deciduous foliage (the leaves stay green in winter) and inconspicuous white flower bunches. The Holly plant has red berries which are symbolic of the blood of Christ) but never eat them no matter how delicious they look because they are poisonous.
The Narcissus ─ Paperwhite
While there are many types of Narcissus, the paperwhite is the winter-growing variety and the birth flower for December.
According to Wikipedia, the Narcissus Paperwhite is part of the Narcissus genus which includes plants known as Daffodils.
The scientific name is Narcissus Papyraceus (from papyrus and aceus; meaning paper-like). The white flowers are borne in bunches and are strongly fragrant. Paperwhites symbolize rebirth and new beginnings. Narcissus in all their varieties are among the earliest blooms to poke through the frozen soil in early spring. It is thus a reminder that no winter freeze can last forever and that warm days and bright sunshine is just around the corner. (info from almanac.com)