Ferns with Ros Bennet

We had a lovely day with Ros Bennet and the Kent Wildlife Trust today, learning to identify ferns in the Kent countryside.

Our first field visit was to Quarry Wood on the Lower Greensand scarp above Yalding, where we found a huge Wild Cherry, which was already on the Kent Heritage Trees database and map.  There were two very large fructifications of Chicken-of-the-Woods, one at the foot of the tree and one much higher up. These fructifications are quite whitish and might actually have been active last autumn. The tree is one of the largest Wild Cherries, Prunus avium, I have ever seen.

Chicken-of-the Woods or Sulphur Polypore, Laetiporus sulphureus, may well be a  group of species rather than just one, according to US research. It is regarded as a saprophyte rather than a major parasite, and may be just one in a longer line of problem that this massive tree has experienced over the years. It was recorded by the Kent Heritage Trees Project 6 years ago, and a split trunk, brown cubical rot and 4 holes were listed then, as seen now. It was recorded as tree 599 recorded by Stephen Foster at TQ7170351838.

More information on some arboricultural fungi such as Chicken-of-the-Woods, https://arboriculture.wordpress.com/category/fungi-2/laetiporus-sulphureus/

This is the tree is its woodland context;

There is a good range of trees on this woodland site, including some very large Ash. This is an old Ash Pollard stool, definitely worthy of note. I do not know why this one was originally selected for pollarding:

We passed one of the specialities of this reserve, Paris quadrifolia,

There were also a few fungi to be found, such as these Ganoderma brackets:

and this "candlesnuff" relative on fallen deadwood, each about an inch or so high, possibly Xylaria longipes:

In one part of the wood we found one "clump" of Hard Fern, Blechnum spicant. The speciality of this species is the split between the vegetative fronds on the outside and the fertile fronds (with obviously narrower "linear" pinnae) in the centre of the clump. Most Blechnum grow from a rhizome, but this particular species grows in a neat tuft. Each of the fertile pinnae in the centre (one is visible here) bear two rows of sori. This species is often sold as an ornamental.

The next fern we were shown was the Male Fern, a fairly simple bi-pinnate structure, with neat rounded-oblong. There are sparse pale scales on the stipe and rachis. This is the (fairly large) shuttlecock, with many vigorous fronds.

Here is a closer shot:

Close by was a shuttlecock of a Lady Fern, Athyrium filix-femina, near an Ash tree trunk, which immediately looks "frillier", possibly tri-pinnate. The species is found across the Northern hemisphere.

I think this is a Lady Fern frond unfolding:

Also quite frilly is the quite robust Broad Buckler Fern, Dryopteris dilatata, with its mitten and thumb pinnulet structure. The stipe and rachis are well covered in golden scales. The sori are covered by a kidney-shaped indusium, as with other Dryopteris species.

Having explored Quarry Wood thoroughly, we moved on.

There are also a number of "smaller" ferns in Kent, quite a few of which may be found growing on walls. This is the Black Spleenwort, Asplenium adiantum-nigrum, growing on a northerly wall of Marden Church. While a little difficult to identify from a distance initially, there is a tidy and relatively glossily green medium-sized triangular frond, and characteristically the stipe is a clean almost glossy black. In fact there are two species of fern here, the Black Spleenwort in the centre, and what might be a Shield Fern surrounding it.

The Spleenwort reveals itself when looked at closely - the pinnae are beautifully set and very similar to the pinnae of the Wall Rue, a much commoner species of Asplenium. It is a bit difficult to describe, but it's the rounded roughly "diamond" shapes of the individual lobes that are characteristic. Overall the frond is roughly bi-pinnate and this speciesn is quite flat or 2-dimensional. That is however quite distinct from the Wall-Rue, when the pinnae are HELD in a specifically 3-dimensional manner.

The green can be quite yellowish - perhaps because of lack of nutrition growing on the wall, as it is normally described as dark green (?).

From the angle above the dark stipe below the green rachis is of course invisible, but was very obvious when the fronds were moved, or from the top, as below.

The form of the fronds can be quite variable - it often seems thinner, with more space in between the branches, and the tip may be more pinnate than bi-pinnate. The other spleenworts (maidenhair and green) are all singly pinnate, and very clearly so.

At Linton Church we found Western Polypody on the wall by the road, although I do not think I will ever be able to tell one Polypody from another. The single fronds emerge singly from a rhizome.

While visiting Linton to look for ferns on the church wall, we had a look down the Lower Greensand scarp across Linton Deer Park on the slope, with its Fallow Deer: