ID of Conifers is a large and complicated subject, but I recently lead an informal Intro to Conifer ID botany outing which was very well received.
I'll be doing it again in the New Year, but for the benefit of iSpotters who don't live in South Oxfordshire (!) here are the basics. Do bear in mind that this is a simplification of a complicated subject!
Before we start, if you wish to learn about conifer ID you really will need a hand lens - a x20 is best, but a x10 will do if that's what you have. They only cost a few pounds for the normal folding type, and the advice to hang it round your neck on string or ribbon really is a good one - it may feel a bit geeky, but if you don't, sooner or later you will put it down in the long grass and lose it. Ask me how I know.. yes, I did it.
And you have to remind yourself of the First Rule Of Botany, which is "Common Names Are Misleading". Closely followed by "and the proper or scientific names keep changing - no use grumbling about it, just deal with it".
Right, here we go.
When we look at trees in general, we split them into two types - they are either Broadleaf or Conifer.
Broadleaf trees have - as you would guess - mostly wide leaves, mostly with veins in a net formation. Conifers have linear leaves: the veins run parallel along their length.
Some people prefer to call them Deciduous and Evergreen.
Like everything in Botany, its not quite that simple: some Conifers are deciduous (Dawn Redwood, and Swamp Cypress for example) and some Evergreens are not Conifers - Holly, for example, or Box.
But it will do for a start.
So, Winter is a good time to look at Conifers/Evergreens, as they are (generally speaking, allowing for the exceptions mentioned above) the green ones, making them easier to spot.
When we look at Broadleaf trees in summer, our first point for an ID is the arrangement of the leaves - are they opposite or alternate?
When IDing conifers, we don't initially look for the arrangement, we firstly look for the type of leaf.
Conifers have three types of leaf - needle, flat, or scale.
(As always, this is a simplification, but you have to start somewhere)
Needles are, as the name suggests, round and pointed. Pine are the obvious ones.
Flat leaves are generally long and thin, but are flattened - Yew would be the most familiar one.
Scale leaves require a hand lens to see clearly - things like the infamous Leylandii have scale leaves.
So the first thing you do is look at the foliage, and decide if it is a needle, a flat leaf, or a scale leaf.
Group 1) Needles.
These are needles - long and thin.
When looking at needles, the first thing is to count how many there are in each bundle.
Check several bundles to ensure you didn't pick an aberrant bunch... they are generally found in 2s, 3s, or 5s (these are all Pines or Pinus) or in clumps of 10 or more - which means Larch (Larix) or Cedar (Cedrus).
So already you have learned an easy ID trick: if confronted with needles, if they are in bundles of 5 or less, you can say with confidence "it's a Pine."
If in 10 or more, is it Larch, or is it Cedar? In winter it is easy to tell - Larch are deciduous, Cedar are not. So if the ground underfoot is covered with dead needles, and you had trouble finding a branch with any good foliage on it, it's Larix. As a broad generalisation, Cedars are stately, shapely trees, often planted in gardens or parks as individuals. You rarely find Larch all alone - it's a cash crop, fast-growing, so it's usually found in plantations - rows and rows of them all together. In addition, Larch have small cones, which tend to stick to the branches even when the needles have fallen, plus they have a habit of shedding branches, so in a Larch woodland, you will usually find plenty of twigs and branches on the floor, all with a number of small cones still in place.
Cedar, on the other hand, have large oval cones which do not fall - they shatter over time, on the tree, so you hardly ever find a compete Cedar cone, you normally only find individual scales:
Group 2) Flat leaves.
Long and thin, but flattened. They usually have two lines of whiteness underneath - these are stomatal bands, or bands (stripes) of stomata, which are the pores through which a leaf breathes. They often show up as silvery against the green leaf, but as so many Conifers have them, they are not all that much use in ID.
This group includes the familiar garden Yew, the exotic Redwoods, the less-familiar Tsuga, and everything we think of as a Christmas Tree, including Firs (Abies) and Spruces (Picea). It also includes my personal favourite, Douglas Fir, which is not a Fir at all. More of that later.
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| Picea omorika - Serbian Spruce |
This is a hand-lens close-up of Picea omorika or Serbian Spruce.
As you can see, long thin flat leaves, and lots of white stomatal bands.
The way the leaf is attached to the stalk is a major factor in IDing this group of Conifers, so we will look at that in more detail later.
So far, I have not been able to come up with a catchy name for Conifers in Group 2, so if any of you out there know of something, do let me know, otherwise I shall have to make something up, and that is simply "not done" in botany.
Group 3) Cupressaceae.
There you go, a nice new word for you to learn. Koo-press-ay-cee. Think about the "press" part of the name, as it contains the clue to this group - it's those with scale-like leaves, or leaves which have been "pressed" against the stem.
As mentioned at the start, it's a generalisation, but the term Cupressaceae can be taken to cover most of those Conifers that don't have either needles or flat leaves. This means (she said with a straight face) that you can look through your hand lens at the foliage and say, solemnly, and instantly, "It's a cupressaceae" which will impress all non-botanists. In fact, you can probably look at a conifer from about five paces, see that it's neither needled nor leaved, and say knowingly "Ah, looks like a cupressaceae from here, but of course without my hand lens I can't tell you exactly which one."
Here's a random selection from the internet:
As you can see, they are all somewhat flattened, the branchlets tend to be in one plane - pressed, you could say, Koo-PRESS-ay-ceee - and the smallest twigs are almost rope-like.
At first, they all look the same, but once you start looking through your hand lens at this group, you will start to see the differences - honestly!
They are a difficult group - but some are easier than others, and some have a strange beauty all of their own, when viewed through a hand lens: here is a close-up of some Calocedrus decurrens or Incence Cedar.
Please note, as per opening statement, that this, along with Thuja plicata or Red Cedar, is not actually a Cedar. Cedars are in the genus Cedrus, and they have needles... I know, I know, you just have to learn to call them by their proper names.
And these strange spiky-looking things, left, are actually common or garden Lawson Cypress, as seen and photographed through a hand lens.
Amazing, aren't they?
Well, that was the briefest of introductions to Conifer ID, explaining the three main groups or types of conifers. Having grasped that idea, we can now start our walk up to the conifer area (heh heh, secret location) to put it into practice.
We will be watching the ground as we go, to see what is fallen: cones and needles are usually very visible, and give us good clues as to what is above.
We look at the foliage and decide if they are needles (if so, how many), or flat leaves, or scale leaves. This gives us a head-start to know which genus the Conifer is likely to be.
And that is quite enough for one post - next time we will look at each of the three groups in more detail.
