Categories
Street Trees

Introducing Hippophae salicifolia – the willow-leaved sandthorn

Our mystery South London street tree has been identified thanks to a correspondent who was able to recognise a fine avenue of Hippophae salicifolia. Several others suggested sea buckthorn (Hippophae rhamnoides) which, as it turns out, was close but discounted due to size (tree rather than a bush), evergreen foliage and few berries. My own guess at a food plant of giraffes was wide of the mark…

Hippophae salicifolia, street tree, London
Word on the Street: Hippophae salicifolia street tree on Curlew Street, London

The positive identification was verified by the Hippophae salicifolia page on Hillier Nurseries’ website featuring a picture of the exact same street tree I had been struggling to identify, apparently there is a 15m specimen to be found at Kew too.

The common moniker that has emerged for this tree is the very unsatisfactory ‘willow-leaved sea buckthorn’. This plant’s natural habitat is dry Himalayan river valleys hundreds of miles from the sea, so I detect botanical imperialism at work in a name relating to our familiar European coastal species more appropriately known as sea buckthorn.

In my opinion our tree needs a new name – Hippophae are sometimes called sandthorn or sallowthorn; our tree is certainly not sallow, so I am proposing willow-leaved sandthorn.

Any takers?

Other Willow-leaved sandthorn (Hippophae salicifolia) resources:

Hippophae salicifolia on the Plants For a Future website
Salicifolia is listed on the Hippophae Wikipedia entry, but there is no separate species page yet.
My willow-leaved sandthorn Flickr set

Categories
Street Trees

Stumped: unidentified street tree

Leaves and orange berry on the mystery street tree
Southwark Leaf and Berry Combo: what is this thorny, evergreen tree with orange berries?

On Curlew Street, in that late eighties enclave of converted spice warehouses just east of Tower Bridge on the south bank of the Thames, I have noticed a curious tree.

Planted, I imagine, when the area was being cleaned up, they look to me like Giraffe fodder: tall trees with long branches, each bearing a sparse canopy of thin, evergreen leaves and the occasional orange capsule of a berry. It would take a long-necked animal with a dextrous tongue to negotiate these thorny branches – not many of them in these parts. And could a tree from the dry plains of sub Saharan Africa thrive in this urban corner Europe?

So what can they be? I have a hunch that the enthusiastic developers of this former dockland took its spicy heritage to heart, and planted rare and exotic street trees to complement the cinnamon, cardamom, ginger and cloves referenced in the new apartment block names. If so it is a reference lost on this flummoxed amateur plant identifier. Or perhaps they are another illustration of Southwark council’s experimental street tree planting programme, as explored in recent posts about Strawberry Trees and the unlikely Persian Silk Tree, to be found in nearby streets.

unidentified street tree, Curlew Street
Evergreen: Mystery trees in Curlew Street

My mystery trees appear to be thriving in this narrow, enclosed street and while I estimate they are up to 30 years old, they look youthful, as if many years growth lie ahead. Given their clear suitability to the urban environment, their elegance and exoticism, they are a species I have not come across before and one whose identity I am, well, stumped by.

I hope the photos in this post will help identification, here’s the Google street view too and you know where to find them if your interest is piqued:

Categories
Street Trees Urban landscape

Red Oak lives up to its name

In a post about the North American Red Oak (Quercus rubra) I wrote in the balmy days of August, I rather flippantly stated that ”… the beauty of this tree in its native New World is surely its fiery autumn colours which in our damper and milder oceanic climate is watered down from a rich red to a pedestrian caramel brown.”

Red Oak (Quercus rubra), More London
Confounded Tree: A Red Oak blatantly turning red

I have been perversely willing all the specimens of Red Oak in London (and I now realise there are a lot) to take on muddy shades in time for bonfire night so I could fill screenloads of blog pixels with an ironic firework-themed, told-you-so posting about the unsuitability of this tree to adorn our streets and public spaces.

Red Oaks (Quercus rubra), More London
Leaf It Out: More Red Oaks making spectacles of themselves with striking leaf colours

Well, there is nothing like humility, so I feel compelled to admit that I have been wrong about Quercus rubra. The Red Oak has come into its own in the past week as the trees I originally wrote about in the More London development are starting to, well, delight. Some trees are deep red, others brick red, more are yellow and orange. What this species lacks in character during the rest of the year, it is now making up for.

That said, I did bump into this rather splendid Acer palmatum or Japanese Maple in Highgate’s Waterlow Park last weekend…

Acer palmatum
Red Alert: Nothing beats the colour of the amazing Acer palmatum or Japanese Maple . This one is in Waterlow Park in north London
Categories
Street Trees

Strawberry trees in Southwark

I was surprised and excited to bump into a row of newly planted Strawberry Trees (Arbutus unedo) in a Southwark street recently. As a child with an interest in native trees, I was fascinated to read about this mysterious tree with a compelling name in my botanical guidebooks. It was described as very rare and hanging on in Ireland where it had survived the last ice age.

Flowers and fruit of European Strawberry Tree (Arbutus unedo)
Cream of the crop: Fruits and flowers of the Strawberry Tree (Arbutus unedo) in south London

They line Melior Street, a short turning in the shadow of the looming Shard, that monument to megalomania that marks the redevelopment of London Bridge station.

Southwark appears to have an experimental approach to street tree planting which I admire: I have never seen the Strawberry Tree planted in London streets before (although this species and other Arbutes are a common feature of San Francisco sidewalks). Earlier in the year I came across a Persian Silk Tree (Albizia julibrissin) in the same borough, and I am now on the lookout for more unlikely foliage that may be lurking in the neighbourhood.

While the Persian Silk Tree is an exotic import with undeniably alien looks, the Strawberry Tree is a native of more familiar landscapes. It is found in the western Mediterranean and the Atlantic fringe from Portugal to, famously, south west Ireland where it is common in parts of County Kerry. It may hail from less far afield, but it was never a component of the post-glacial Bermondsey forest and consequently the Strawberry Tree’s evergreen foliage and drupe-like berries provide unexpected lushness to its adoptive environment.

Characterised by bushy growth in the wild, Southwark’s trees have been trained or grafted to produce 2 metres of straight trunk before this characteristic is allowed free rein. The English name arises from the appearance of the round pitted fruits, but they are actually part of the Ericaceae family and therefore related to the heaths which becomes apparent in the white bell-shaped flowers. A lovely feature of this Arbutus is the simultaneous flowering and fruiting in the autumn, the fruits take twelve months to ripen and go through every conceivable shade between lime green and vermillion. At this time of year, the trees sport a jaunty array of ripe red fruits interspersed with citrus coloured baubles and bunches of white flowers. Gorgeous.

Strawberry tree (Arbutus unedo) street tree, Bermondsey
Strawberry Daquiri: Arbutus unedo guides the thirsty into the Horseshoe Inn

Here’s the view down Melior Street from Google streetview showing the newly planted Strawberry trees:

Further reading:

Map of native and non-native records for Arbutus unedo in Britain and Ireland on the Biological Records Centre website
Description of the magnificent and elderly Strawberry Tree in Waterlow Park, Highgate
Wikipedia entry for Killarney National Park where native Irish Arbutus unedo is found (needs some editing!)
My Flickr photoset including Arbutus unedo

Categories
Urban landscape

Trees of Heaven

That tenacious suckerer, the Tree of Heaven (Ailanthus altissima) has been at it all over London.

Tree of Heaven (Ailanthus altissima), Finsbury Estate, London
Bedded in: ToH enjoying the company of some lurid Dahlias on the Finsbury Estate

Since my last post on the Tree of Heaven, I have been seeing them everywhere. They are invasive and potentially damaging, but they appear to be tolerated, even encouraged by Londoners. It’s not just in the privacy of domestic gardens; the ToH manages to blend in to civic planting schemes just as sneakily.

Check this chancer out on the underground reservoir bank at the corner of Amwell Street and Claremont Square in Islington:


Since the Google street-view was taken in 2007/8 (I think?) this one has grown into a medium-sized tree blending in effortlessly with its older, planted neighbours. Only its position so close to the railing gives away its interloper status.

Further down Amwell Street I saw another opportunist thriving in a crack between the pavement and a basement wall of a Georgian townhouse. Unusually I couldn’t locate the parent tree for these Amwell Street tenants, maybe it’s in a back garden or perhaps these are suckers from a street tree now removed.

The success of the Tree of Heaven seems to be its ability to appear inoffensive, its attractiveness helps too, but perhaps it is its brazenness that works best for it. It will just pop up surprising a new landlord or landlady and rapidly take hold growing metres per year in some cases.

Tree of Heaven (Ailanthus altissima), Amwell Street, London
To Let: ToH opportunistically squatting in a basement wall of a fine Georgian house in Amwell Street

I suspect there will be more ToH posts in the future, and I have started a leafy invader Flickr set which I will be adding to in the meantime.

Categories
Countryside

Sycamores in the British landscape

Soon after I first became interested in plants and conservation I became aware of the concept of native and non-native species. I grew up in Dover, a port town where xenophobic attitudes are paradoxically ingrained in a population who perceive themselves to be on the frontline of an unfinished European war and are ever ready for an imminent invasion of unintelligible foreigners, so I was used to this concept and knew what was expected of me.

Sycamore (Acer pseudoplatanus) in northern England
Sycamore (Acer pseudoplatanus) on the march in northern England

In the local woodlands the unfortunate Sycamore was singled out as a non-native species, a recent invader from Alsace, Franche-Comté or maybe even further afield. Europe’s largest maple was intent on ousting our native, British trees through unseemly reproductive vigour unmatched by our altogether more restrained climax vegetation.

I made it my patriotic duty to single-handedly eradicate the Sycamore menace from local woodland where each spring thousands of seedlings would threaten the native Beech (Fagus sylvatica), Ash (Fraxinus excelsior) and Yew (Taxus bacatta) woodland defined 10,000 years ago. Or so I thought at the time. In reality Sycamore does throw out many, many seedlings every year but these cannot survive to maturity in the shade of Yew and Beech. Sycamore is a coloniser of disturbed or open woodland and can act as a very good nursery plant for our more shade-tolerant but less fecund woodland trees. Sycamore does not therefore colonise our woodlands, but rather becomes a component of them with a part to play in the real and inclusive ecosystem. And of course our woodlands – ancient or otherwise – have been shaped by Man for our own, usually sustainable, exploitation for millennia.

Sycamore (Acer pseudoplatanus) near Hadrian's Wall
Lone Sycamore (Acer pseudoplatanus) giving it's name to Sycamore Gap on Hadrian's Wall

On my recent tour o’ the North, I was struck by how important to the upland Pennine landscape the Sycamore is, it has been a part of the scene for generations. It takes on the appearance that Oak does further south where ancient and dignified trees stand sentinel in a field or as a roadside reminder of a long ago grubbed-up hedgerow.

So my view of the Sycamore has changed – I appreciate the part it plays in the landscape, it is a familiar tree to many and it is not invasive, which is perhaps the measure of how we should judge the menace posed by plants. Sycamore may not appear in prehistoric pollen records, but its arrival on British shores is a mysterious event that cannot be dated.

Looking north to Sycamore Gap on Hadrian’s Wall from the former Roman military road:


There is a very interesting white paper published by the Woodland Trust on their website for those who may like to read more on the subject.