treeblog - All posts tagged: elder

Travelling through Sheffield and Hillsborough on the bus this afternoon, I noticed that ~~common~~ alders (probably Italian alder, Alnus cordata) have deployed their bright yellow male catkins. Each tree was covered in thousands of these long yellow pollen-dispersers, and they looked super. Determined to capture the glory on film (XD card), I took a walk down Ewden with my pa, aiming for the alder carr around Salt Spring Beck, Owler Carrs. Upon arrival, I was disappointed to see that these common alders (Alnus glutinosa) were lagging behind their urban heat island chums in the city, phenologically speaking. The male catkins were still in their compact, red wine-coloured winter forms – photograph please:

But then – aha! Right by the beck, a young alder with a fair smattering of the yellow spring-form catkins. Not as tree-coveringly many as I saw in Hillsborough and Sheffield, but still plenty. Camera out, close-up shots ahoy. In the bag.

Later on, walking down the steep part of Mortimer Road towards Ewden Bridge, we spied another young alder with long yellow male catkins. Stopping to admire these early signs of spring, we noticed an unusual bud – the only one of its kind on the tree, as far as we could tell. It looked just like all the other buds, except for little red spikes poking a few millimetres out of its end. Puzzling.

Fast-forward several hours, and here I am uploading the day’s photos onto the computer. Before writing a post around the catkins, I thought it would be good form to see if I could find out what those red spikes were all about. A flower? A gall? A few googles couldn’t shed any light on the matter, but then I had an brainflash. What if that weird bud wasn’t on an alder, but was on a hazel. They both have long yellow catkins in spring…

Lolz. It turns out I’d been fooled. The Mortimer Road alder wasn’t an alder after all, but a hazel (Corylus avellana). Duh! The bud with red spikes? A female flower! Which, all things permitting, will develop into a hazelnut in the summer. (My Collins Field Guide Trees of Britain & Northern Europe, by Alan Mitchell, describes the female flowers as “brown ovoids 3-5 mm with bright deep red styles exserted 2mm a few days after pollen of same tree is shed.” And my Collins Tree Guide, by Owen Johnson, correctly likens them to “crimson sea-anemones”.)

Then the thought hit me that if I was wrong about this alder-hazel, could I also be wrong about the one at Salt Spring Beck. Yes I could. It’s all in the buds you see. Once I’d IDed the Mortimer Road tree as a hazel, I saw that its buds were green and scaly. Just like the ones in the background of the photograph of male hazel catkins at the beginning of the post. Alder buds are smooth and purple – you can see a couple in the photo of the red wine-coloured catkins, which actually are alder catkins. In a week or so they’ll open up, getting longer and exposing their bright yellow insides – just what has already happened on the alders I saw on the bus, which were definitely alders and not hazels because of their giveaway single-stem mode of growth and distinctly alderish shape.

A closer look at the top of the catkins, revealing the golden, pollen-carrying anthers.

What a waffly post! The quick version: man sees catkin-laden (Italian) alders in town; goes on walk to get photos of (common) alders; thinks yellow-catkined trees are young alders; transpires they were actually hazels. Thank the Man-Jesus for those little red spikes. New tree knowledge: what alder and hazel buds look like, and what female hazel flowers look like. Other signs of spring seen: elders (Sambucus nigra) have begun flushing.

Derwent Dam tree photographs

Derwent Reservoir, in the center of the Peak District, has quite an unusual style of dam wall. Instead of the grassy embankments used to dam most reservoirs in the vicinity of the Peak District, the dam wall at Derwent (and neighbouring Howden Reservoir) is much steeper and faced with huge stone blocks. Large gothic towers loom at either end of the dam wall, and in wet weather, water overflows between the towers and cascades down the great stone wall in a magnificant spectacle.

During World War II, Derwent Reservoir was used for bombing practice by the RAFs 'Dambusters' (617 Squadron). The dam at Derwent was used as it was of a similar design to those in Germany's Ruhr Valley, which were to be the target of RAF bombing raids; with the dams destroyed and the reservoirs empty, it was hoped that German industry would be seriously impeded and thus their war effort hampered.

The barrel-shaped 'bouncing bombs' used by the Dambusters were designed by Barnes Wallis. The bombs were dropped spinning rapidly backwards at a low altitude in order for them to bounce over the reservoir surface to reach the dam wall. They would then spin downwards to the base of the wall before detonating.

I visited Derwent Dam this afternoon and took these photographs. Thanks to the recent very wet weather, the water rushing down the dam wall made for a very impressive sight.

Blackford Hill gallivanting (3rd May 2007)

The young leaves of a small sycamore which was decapitated when a patch of gorse was cleared. The sycamore is a lot quicker off the mark in terms of recovery, by the look of things.