Botanical Accuracy: What Christmas tree is that? A guide to common species

Tuesday, December 24, 2013

What Christmas tree is that? A guide to common species

Christmas trees come in many shapes, colors, and species these days. In the old days you went out into the forest and cut a little (usually rather scraggly-looking) tree of some native tree in your local forests.

Postage stamp from Åland (between Sweden and Finland) showing people
(with saw in hand) bringing home the Christmas tree.
(c) Posten Åland, fair use (link)

For example, in Northern Europe you have only one local species of pine (Scots Pine, Pinus sylvestris), and only one spruce species (Norway Spruce, Picea abies), so a wildcut tree would be one of those species. Unless you brought in a juniper of course (Juniperus communis). In North America there are more local conifers to choose from, but still mostly only a handful. But these days things are not so simple.

Nowadays, the Christmas tree plantations grow a wide variety of conifer species that might not be local to your area. If you get a tree from a supplier, then the tree might come from far away. So, finding out what tree you have standing in your living room might not be that simple.

The National Christmas Tree Association has nice photos and descriptions of the most common species. Brooklyn Botanic Garden also has a great clickable key to Christmas tree species with images and descriptions of 15 common species. (Update: Max Payne also has a nice page with descriptions of common Christmas tree species, including several Cupressaceae species.)

First, most Christmas trees are either FIRS (Abies), SPRUCES (Picea), DOUGLAS FIR (Pseudotsuga). or PINES (Pinus). All of these are conifers and have leaves called needles, and cones (except, you rarely see cones on young trees used for Christmas). These plants are quite easy to tell apart and they all belong to the pine family, Pinaceae. See key below.

US Postal stamps showing balsam fir, blue spruce, ponderosa pine and eastern red cedar.
(c) USPS, fair use (link)

Identification key to common Christmas tree genera

1a. Are the needles clustered 2-5 together? Yes - it is a pine (Pinus).
1b. Are needles single? Yes - it is a fir, douglas fir, or spruce. Go to 2.

2a. Are the needles square in cross-section and green underneath? Yes - it is a spruce (Picea).
2b. Are the needles flat in cross-section and have two white bands underneath? Yes - it is a fir or douglas fir. Go to 3.

3a. The buds at the end of each branch have a sharp tip and are elongated. Yes - it is a douglas fir (Pseudotsuga).
3b. The buds at the end of each branch are blunt at the apex and round. Yes - it is a fir (Abies).

White pine.
Public domain image by Hardyplants, Wikipedia.

PINES (needles grouped in 2-5's)
Needles 5 together:

White pine (Pinus strobus) - green to bluish green, needles 5 together, 5-12 (2-4") cm long

Needles 2 together:

Scots pine [older name: Scotch pine] (Pinus sylvestris) - green, sometimes silvery, needles 2 together, 4-7 cm (2-3") long
Virginia pine (Pinus virginiana) - green to yellowish green, needles 2 together, 4-7 cm (2-3") long

Norway spruce branch.
(cc) Wikipedi, Wikipedia.

SPRUCES (needles single, square in cross-section, no white bands below each needle; each needle attached to the branch on a little outgrowth; needles attached spirally around branch)

Bluish or greyish tree

Colorado blue spruce (Picea pungens) - blue green, needles 2-3.5 cm (1-1 1/4") long, with sharp tip
White spruce (Picea glauca) - bluish to bluish green or gray, needles 1-2 cm (3/8-3/4") long, with blunt tip

Green tree

Norway spruce (Picea abies) - dark green, needles 1-2.5 cm (1/2-1") long (drooping branches)

Douglas fir branch with cones. The cones are unique,
look at those bracts hanging out betweenthe scales, nothing else looks like that.
(cc) Walter Siegmund, Wikipedia.

DOUGLAS-FIR (needles single, white bands below each needle)

Douglas-Fir (Pseudotsuga menziesii) - green to blue green, needles soft, 2-4 cm (3/4-1 1/4") long

Needles of White Fir showing white lines underneath.
(cc) Walter Siegmund, Wikipedia.

FIRS (needles single, flattened; white bands below each needle; each needles attached directly to the branch; needles attached in two rows along branch)

Needles with two white lines above

Concolor Fir [White Fir] (Abies concolor) - green to bluish green, needles 2-5 cm (1 1/4-2") long (needles with sharp apices)
Caucasian Fir ["Nordmann"] (Abies nordmanniana) - dark green, needles 1.8–3.5 cm (2/3-1 1/2")

Needles green or silvery above, without lines

Balsam Fir (Abies balsamea) - dark green, needles 1-4 cm (3/8-1 1/2") long (needles with blunt, notched apex)
Fraser Fir (Abies fraseri) - silvery to dark blue green, needles 1-2 cm (1/2-1") long (twigs with red hairs)
Grand Fir (Abies grandis) - green, needles 2-5 (1/2-2") cm long (twigs with grey hairs, needles with blunt, notched apex)
Noble Fir (Abies procera) - silvery, needles 2-4 cm (1-1 1/2) inches long (needles turn upwards along branches)

(Not included in this blog post are cedars, junipers, and yew, since they are less common as Christmas trees.)
Post updated 28 January 2014 with new information provided by MF.

What is Botanical Accuracy?

Would you care if someone called a cat 'a mouse' in the description of a medieval painting?

Would you care if someone served you horse meat, but said it was beef? I bet you would.

Would you care if the wrong chemical was listed in the ingredient list of your shampoo or cereal?

Would you care if you bought one plant, but got another?

Would you care if there were species or ingredient mistakes in advertising, menus, herbal pills, and such things?

Would you care if books on plants are illustrated with the wrong plants?

If so, here is the place for you to read about such problems in the world of plants and plant products, where unfortunately such mistakes, inaccuracies, and problems are not uncommon. This is usually due to lack of botanical knowledge or expertise, or sometimes because of plain ignorance.

Inaccuracies are common when it comes to plants, because it seems like we humans care to learn less about green things like trees, flowers, and herbs than we care to learn about animals, even when we eat plants, paint them, plant them, extract their chemicals, or use them in numerous other ways.

Without plants in the world you and I certainly would be dead. Some plants can also kill you with their toxins, so it is best to know which plant is what species. Time to learn some botany!

About mistakes, inaccuracies, and errors

Science is a process of gaining knowledge and understanding of the world around us. It is a never-ending process, and what we think are true facts today might change tomorrow. In science we are aiming for having the best understanding possible today based on what we and our predecessors have learned until now.

This means that what is botanically accurate from a scientific viewpoint might (and will) change. Other experts in the field of botany know a lot more about their particular research plants than I do. New scientific findings and conclusions are being published every day. This is just normal and part of the scientific process; we improve on our knowledge all the time.

The important thing is our willingness to continuously aim for botanical accuracy and the highest scientific standards in our use of names and facts. When things are wrong, let's correct them. Let us not perpetuate wrong botanical knowledge by accepting its incorrect use on commercial products, in everyday language, or in other parts of our contemporary cultures. Through scientific education and specific corrections we will improve botany and science for everybody, in supermarkets, restaurants, and garden centers.

It is the perpetuation of incorrect facts that are the problem, not the need for correction. Everybody makes mistakes, and everybody learns, throughout their lives. We need words to be able to communicate and talk about things, so let's use the right words and the right species names.

Undoubtedly there will be mistakes and errors on this blog, or things that need to be updated. If you want to get in touch, please e-mail me at botanicalaccuracy at gmail.com. If you see a mistake on this blog, e-mail me with the link to the post and an explanation what is incorrect and should be updated. If you represent a company and want to get in touch, please use the same e-mail address.