Christmas plant basket

Hi CanadianGran, the fluffy plant is a Selaginella, possibly S. kraussiana, commonly known as club moss or spike moss (it's not a moss actually) and related to the Resurrection plant.
They are really suited to terrariums, as they need high humidity, so it may shrivel a bit grown in the open. It's so annoying when plants with such different requirements are grouped together in an arrangement, purely for aesthetic purposes, so it will be a good idea to separate them after Christmas, as you say.

Yes, I remember seeing poinsettias in Mexico growing naturally. They did not much resemble the short bushy plants known to all of us as Christmas plants. Instead they were tall and lanky, much like your photo above.

After Christmas, I will separate the four different plants in my basket and re-pot them.

Hi CanadianGran lovely basket. It's not easy to identify the plant from the photo on my device. I use an app called Plantsnap to identify plants (there are other similar apps). It is really useful.

As an aside, where I am originally from on the East Coast of South Africa, pointsettias grow as tall as can be, and are planted in a criss-cross pattern to form a hedge, similar to in the attached photo. I almost feel sorry for them when I see them grown in a pot! (Although I am sure it is a different variety).