We all know ferns and we all know bracken. But how can we tell the difference between the two? Easy, says Dave our woodland tree and plant specialist. Just compare the pinnate.
The pinnate is the feather-like leafy bit that comes out of the stem. Ferns are bi-pinnate, which means that the leaflets divide twice to produce the easily recognised fronds. Bracken, on the other hand, is tri-pinnate. This means that the leaflets divide three times, giving each frond its own tiny frondlets – like a little green comb.
See if you can tell which is which in the photograph below. The answer’s at the bottom.
Answer: The bracken’s at the top and the fern’s below. Did you get it right? Leave a comment to let us know.
Hi :In addition to the pinnate being the distinguishing feature, can one also distinguish between bracken & fern by the thin (usually) stems them that bracken seem to have unlike ferns?
Fred
Yes – that was easy – thanks very much!
Nope, sorry, I’m not seeing it. Got another example?
Well, sorry to be a grump, but there’s rather a lot that’s, er, not quite right about Simon’s original posting.
1. You can’t talk about telling Bracken from ferns. Bracken _is_ a fern – in fact, the boss fern, occurring in more parts of the world than any other. That’s not just pedantry, as we’ll see shortly.
2. “Pinnate” is an adjective that says that a leaf or blade is divided down into separate segments. You can’t talk about “a pinnate”. If you go to a flora or field guide to help you out on this, it won’t mention “pinnates” – the usual terms are “frond” or “blade” for fern leaves.
3. Yes, Bracken is 3-pinnate (its leaves divide down three times). Unfortunately, you can’t tell that from the posting, as the photo doesn’t show the whole frond and you can’t see the first division. No wonder Janet was struggling.
4. According to species and sometimes even varying a bit within species, other ferns can have leaves that are entire (completely undivided); lobed but not pinnate; 1-pinnate; 2-pinnate; 3-pinnate; or 4-pinnate. A very common example of a 3-pinnate fern that isn’t Bracken, found pretty well all over Britain, is Broad Buckler-fern.(Actually, the last division of the leaves is often only part-way to the base, in Bracken or in other ferns, Books sometimes refer to this as “2-3” or even “2 1/2” pinnate, or whatever times and a half it is.)
So, how _do_ you tell Bracken from other ferns you might come across?
1. Its fronds come up singly, not in tufts or “shuttlecocks” like many other ferns.
2. It’s 3-pinnate (yes, that certainly does narrow the field down a lot).
3. Take a mature leaf and look at the underside. That’s where, on most ferns, the spores are The spores are the things which, after a complicated life-cycle, eventually give rise to baby ferns. They are massed together in clumps or lines, in some species with a membranous lid or flap covering them. The patterns these form are often distinctive. In the case of Bracken, the spores occur in a continuous line around the edge of each leaf-segment, and are covered by a continuous flap formed partly by a very narrow membrane and partly by the edge of the leaflet being rolled over. If you’re unlucky and get a frond that’s not sporing, the rolled-over edge is still there (as long as the frond isn’t very young).
In answer to Fred’s question, the stem of Bracken is actually pretty robust compared with many other ferns.The other fern illustrated is either Male Fern or a Golden-scaled Male Fern. These can have stems that are either more or less robust than Bracken – one species of Golden-scaled is certainly very chunky.
– Martin Rand
BSBI Recorder, South Hampshire
Well a bracken IS a fern, but here is the difference:
So as you can see in the picture, bracken has the stem, then the fronds that protrude from the stem, then the pinnate leaves protrude from the fronds’ ‘stems.’
Do you all get it now, if you didn’t?
Glad to help those puzzled people 🙂
Oops. I forgot to tell what the fern is. X3
So that was the bracken;
A fern has only the stem and the pinnate.