The River Plym near Cadover Bridge

I was at Lower Cadworthy Farm earlier in the week to meet a former National Trust colleague to discuss a project I am working on for the NT. Lower Cadworthy Farm is owned by the NT and run as long term volunteer accommodation. It was lovely bright day and after the meeting I had a short walk down to the river.

Lower Cadworthy Farm – refurbished and run by lots of green technology – see here

The River Plym runs past the house at the bottom of the field

Note that the sessile oaks are yet to come into leaf – the green in the trees you can see in the photo is ivy

The fringe next to the river shows historic signs of tin streaming

And also the remains of a leat used to power a mill

Oak trees slowly coming into leaf – we’re in for a splash

Ash before oak – we are in for a soak

Oak before ash we are in for a splash

In reality oak pretty much always  comes into leaf before ash. In the last fifty years oak has always leafed before ash. It has not always been this way – in the 18th century when it was less mild ash did often flower before oak – thus the quote.

Climate change has changed all of this – usually oak leafs in late March-May which is about two weeks earlier than 30 years ago. Ash usually leafs during April and May, about 7-10 days earlier than 30 years ago.

In my garden I have 5 large oak trees and a couple of ash trees. 3 of the 5 five oaks are now in leaf  but none of the ashes are.

Green splashes on the oak trees.

Pedunculate (or English oak) in leaf and in flower

Not often seen – the flowers of the Pedunculate oak

The two oaks in my garden which haven’t come into leaf yet are clearly a different genetic stain from those which have.

Here are the Sessile Oaks of the Teign Valley at Fingle Bridge – a few hundred metres higher in altitude and not yet anywhere near leafing – spring is a long drawn out process …..

 

English oak and acorn

A couple of  weeks ago I wrote about sessile oak and its acorns – see here. Here are a couple of photos of English (or Pedunculate) Oak and its acorns for comparison.

English Oak – leaves have short stalks and the acorns have long stalks

Long stalked acorn = English oak

For comparison – sessile oak – long stalks on the leaves  – short stalks on the acorns

 

 

The sessile oak, its acorns and the NT logo

In June this year I did a blog on the two different types of native oak in Britain – the predunculate oak (Quercus robur) and the sessile oak (Quercus petrea) – see here for the details.

In that article I explained how to tell the two species apart: pedunculate oak – short leaf stalks and long acorn stalks; sessile oak – long leaf stalks and short acorn stalks! Pedunculate oak in the lowlands and sessile oak in the uplands.

The acorn season on Dartmoor is now in full flow – here is a sessile oak from Cod Wood in Fingle Woods – long leaf stalks and short acorn stalks!

Acorn stalks couldn’t be any shorter!

This oak almost looks like the National Trust logo! But look a little more carefully – long leaf stalks and short acorn stalks = sessile oak

 

Here is the NT logo – long acorn stalks and short leaf stalks = pedunculate oak!

So an oak is an oak – yes?

Think again – Dartmoor (and the UK generally) has in fact got two species of native oak (Genus Quercus). One species the Pedunculate or English oak (Quercus robur) is the species of  lower more nutrient rich ground whilst the Sessile oak (Quercus petrea) is an upland species found on nutrient poor soils. Sessile oak is the quintessential species of Dartmoor’s river valleys (e.g. the Teign, the Dart and the Lyd). With a bit of practice and knowledge it is quite easy to tell the two species apart.

 These are the leaves of Pedunculate oak (Q. robur) – note the leaves have very short stems where they meet the twig/branch and have little ears called auricles where they meet the twig – you can see the auricles at the centre of this photo where the four leaves join the branch

 A single Pedunculate oak leaf – note no stem to the leaf – the auricles are at the left end of the leaf in this picture. In addition the underside of the leaf and its veins are hairless.

These on the other hand are the leaves of the Sessile oak (Q. petrea). Note there is a stem over 1cm long which joins the leaves to the twig

A single leaf of Sessile oak – stem and no ears! On the underside of the leave along the veins are numerous star shaped hairs.

There is another essential difference between the two species but one which I won’t be able to show you until the autumn – this involves the stalk on the acorns. The Pedunculate oak has a long stalk to connect the acorn and cup to the twig whilst the Sessile oak’s acorns and cups are stalkless.

In summary then….

Pedunculate oak: short stems to the leaves, auricles, hairless and long stalk on the acorns
Sessile oak: long stems to the leaves, no auricles, star like hairs on the undersurface veins, no stalks to the acorns

Where to see the two species:  there are plenty of Pedunculate oaks at Parke (but beware the parkland contains a number of exotic species of oak too (e.g. The Lucombe Oak, Turkey oak and Holm oak) but they look very different. You can find Sessile oaks in the Teign Valley including Fingle Woods, Lydford Gorge, Hembury Woods and Holne Woods. These woods also contain some Pedunculate oak so are perfect places to practice your ID skills!