Purging Buckthorn… again, and a sap green sketch.

Yesterday I wrote about my Purging Buckthorn Rhamnus cathartica and the “sap green” pigment which was once extracted from its berries.  Today a few more notes.
In this mild autumn the spinney by the shed still has quite a few leaves. If you are drawing trees it’s a good idea to sketch the whole thing because they all have very different overall shapes.  It’s a way of getting to know them.

buckthorn and shed bg      leaf bg

Some leaves are still green, some have turned yellow and do look quite pretty, and some are in-between, with delicate two tone patterns. (I did use some sap green in this sketch.. the modern version though.)

buckthorn leaves

The bark of the mature tree/shrub is actually quite attractive. It is dark almost glossy, a dark purple brown and striped with prominent pale lenticels.
These are raised pores on the surface of bark which facilitate the exchange of gases from the inside of the plant to the outside and vice-versa. There are a lot of them on this plant.
Some have greened over with lichen. The spines seems to grow on every part of the plant, below a sketch of a small branch we pruned yesterday. One massive thorn is 5 inches long very robust and very sharp.
The immediate cut surface of the bark is a cinnamon brown. The largest clump of buckthorn comprises a group of 5 or 6 trunks twining affectionately around each other. We took about 10 smaller ones out yesterday and have liberated the small shed.


bark and spines buckthorn sm

Twigs are good things to draw and if you are interested in identifying winter twigs you can download this very nice free chart from the Woodland Trust here

winter twigs woodland trust

Winter twigs Woodland trust It was much colder today.. our first UK winter for 8 years is definitely on its way. Brrr…

Getting to Know the Garden: No 1, The spiny “Purging Buckthorn”.

It’s one of the first things to do with a new garden. Go out and see what you already have. I am starting, sensibly with things that still have leaves.

To the left of the shed there is a tall scrubby, straggly, suckering, thorny thing which apart from the depressing leylandii on the eastern boundary is the biggest thing in the garden.

I am pretty sure it is a buckthorn, Rhamnus cathartica I think.
It has sent up long side shoots forming itself into a little spinney which is slowly surrounding and imprisoning the small tool shed.. (Yes I am a two shed girl! lucky me..) You would not have noticed the little shed before some of the leaves fell from the buckthorn.  It was quite a surprise to find it.

However I am not a big fan of this shrub..each branch is armed with vicious spines and it is no beauty.. but it is a native tree and is the food source for both Brimstone butterfly and equally spiny Tiger Moth caterpillars. Hopefully in the spring I will see some of these pretty brimstone butterflies feeding on the flowers.

220px-Gonepteryx_rhamni_mounted      187px-Gonepteryx_rhamni_-_caterpillar_01_(HS)

Brimstone Butterfly and its caterpillar feeding on buckthorn. Images by Sarefo and  Harald Süpfle from Wikipedia.

Why Purging Buckthorn? Because its bitter black berries are an alarmingly good purgative…one I have not yet tried, I hasten to add…
Then, just after I had my flesh ripped to the bone by one of its thorns and was wondering if it should all be dug up, and burnt,  I read  this:

Sap Green, Or Verde Vessie, is a vegetal pigment prepared from the juice of the berries of the buckthorn…. It is usually preserved in bladders, and is thence sometimes called Bladder Green; when good it is of a dark colour and glossy fracture, extremely transparent, and of a fine natural green colour. Though much employed as a water-colour without gum, which it contains naturally, it is a very imperfect pigment, disposed to attract the moisture of the atmosphere, and to mildew; and, having little durability in water-colour painting, and less in oil, it is not eligible in the one, and is totally useless in the other.

from Chromatography or, A treatise on colours and pigments, and of their powers … By George Field, 1835 read more from Google books here.

Well how fascinating! And there are many other references to sap and bladder green and to the dyes which could be obtained from this unfriendly plant.
Other accounts are not quite so damning. OK, so a reprieve for this now-more-interesting shrub, for a while, at least. My friend John over on his blog Nuncketest who is busy making his own paints might just note this down for a bit of an experiment :).
I know buckthorn has gone “invasive” in the USA…maybe just another European who saw those high, wide and fabulously open spaces and understandably went wild. Who can blame it.
This particular European is feeling a little hemmed in, having been put firmly back in her small UK box, for now.

Purging Buckthorn, Rhamnus cathartica

Only a quick pencil sketch and notes for now. I have spent all day trying to get the heating sorted out and weather proofing the sad neglected fence.  Tomorrow, hopefully a “sap green” sketch..

purging buckthorn bg