Picea is the Latin name for the spruce, and a ‘Christmas Tree’ or a Norway Spruce to give it its other Common name is a particular species of Spruce. If you look at the Latin name, Picea abies, what it is saying is that this type of tree is ‘The Spruce That Looks Like a Fir Tree’.
Back in the day, the name ‘Chistmas Tree’ only ever referred to The Norway Spruce, and to this day, Norway still gives the tree each year that stands in Trafalgar Square in London every Christmas as a ‘Thank You’ for liberating them at the end of the Second World War.
Nowadays, many other types of conifers are offered as ‘Christmas Trees’, mainly Fir Trees.
This is the foliage as new growth appears in the Spring.
And these are the cones, which in the Spruce, hang down