Going Urban - part 2

 In the last post I touched on plants that find niches in urban environments by growing in cracks and various other nooks and crannies in our human world. The second group of plants that can be studied and recorded in urban environments are initially planted but eventually become a part of the landscape. Many people who get involved in plant surveys don't record such things, which is a shame, because they are certainly a part of the world around us and they will be having an effect on any number of things, especially populations of insects that may find them appealing. It is also worth noting that the Botanical Society of Britain and Ireland (BSBI) certainly encourage street trees to be recorded.

My recent visit into Cromer on the North Norfolk to get the car its annual MOT certificate gave me the opportunity to do some plant recording in town and to muse on a few things regarding urban botany, this time looking more at the exotics that come into our everyday lives, rather than the colonisation of our space by native species...

Linking in from the last blog post, as this is a plant on a wall, is this Felicia petiolata. One of the benefits of recording non-native plants in urban environments is that it gives us a chance to monitor the progress of these species. Many will be pretty innocuous and cause no problems for the environment around us, but every invasive alien started somewhere and we can acquire a lot more accurate data on the rate of spread of a species (or otherwise) if we record it right from the start. Felicia petiolata (which appears not yet to to have earned itself an English name!) is a relatively recent addition to the suite of plants available to gardeners through the horticultural trade. I found this plant where it had self-seeded into a lovely old Norfolk wall in Stiffkey nearly five years ago and it will be interesting to return at some point and see if it is still thriving. This species is from South Africa and is sold as a half-hardy plant for hanging baskets, but it does seem to be starting to get through our winters OK and it is a perennial, so could become the next Mexican Fleabane!

One obvious barrier to becoming established is hardiness - the ability of a plant to survive cold weather. For plants from warmer climes, this can be a major issue, although many plants are able to withstand periods of cold, even ice and frost, if they are dry and it is the UK's wet winters that can be a problem for them. This species is Giant Viper's-bugloss Echium pininana which is native to La Palma, one of the Canary Islands. For many years now it is done well in the milder parts of south-west Britain, but winters are getting milder and plants are not only surviving the winter to attain flowering size (which takes two to three years) but its seeds are germinating and young plants are starting to appear outside of gardens in a number of places, even here in East Anglia. This plant is in my garden, but it shows how frosty weather can make it have second thoughts! (The wilting of leaves is actually a good strategy to protect the stem of the plant from the worst of the weather)

Palm trees are perhaps one of the most iconic indicators of a tropical or sub-tropical climate and are popular for use in holiday hotel gardens in warmer regions of the world. The so-called 'English Riviera' in South Devon once prided itself as the only part of the UK where palms managed to survive reasonably well, thanks to a coastal climate and the effects of the Gulf Stream. But times are changing and is clear to see in the plants that local authorities choose to spend money on. At first, palms were a brave choice and only for the mildest of coastal towns, where no doubt a few extra degrees of warmth from the urban environment helped them survive. Such plants were also often lifted and placed under cover for the winter, or heavily lagged in hessian to help them survive the worst of the winter weather. Such cultivation techniques essentially rendered these plants unrecordable to botanists since they are clearly not surviving without help, but this is not so much the case any more. Chusan Palm Trachycarpus fortunei from China has coped with UK winters for many years now and recently I even found some self-sown seedlings from one. But other species are starting to appear and this picture shows Dwarf Fan Palm Chamaerops humilis which is a Mediterranean species of warm, stony places. I think that, as well as recording the presence of these street plants where they are clearly continuing to grow unaided through cultivation, it will be useful to establish what year they were planted as an aid to monitoring how survival might change over time - another useful addition to phenology projects.

As things get more exotic in response to our changing climate, local authorities get more ambitious with what they are prepared to put out onto our streets. With my botanist's hat on, this offers up a great opportunity to delve into unknown areas in search of identifications! From a distance, I assumed this tree would be one of the date palms in the genus Phoenix, since they are reasonably tolerable of cold weather and the species from the Canary Islands is quit popular as an ornamental. After taking a few close-ups of some of the finer details, I delved into the scary world of palm identification and realised that it's a species of Butia from southern South America. It's a difficult group so I'm going to have to wait for the fruits to develop a little more but I think it's going to be either Butia capitata or Butia yatay - time will tell, and time will tell if it thrives but it's already survived a couple of winters at least, I believe.

Some plants are smaller than trees but they are still perennial plants with permanent above-ground structures so are worthy of recording where they are clearly not being cultivated and tended. The New Zealand Flaxes were introduced to the UK in great quantity in the 1970s and since then have become familiar sights around the country. Again, they are a little susceptible to winter weather damage, so recording will be an interesting way to see how they are coping here. As with the palms, the presence of these plants has meant time spent delving into identification sources for plants from other countries and it is amazing what is possible now that we have the internet. Although I checked on the progress of this plant in Cromer on my recent visit, this photo was taken last summer as the flowers are the feature that best allows us to tell the two species that we have in the UK apart from each other.

A closer look at the Cromer plant reveals the flowers to be mostly yellowish in colour and with petals that are quite strongly recurved at the mouth of the flower. These features - as well as the relatively short height of the plant overall - make it Lesser New Zealand Flax Phormium colensoi, which is often grown on a range of forms with variegated or coloured leaves.

For comparison, these are the flowers of New Zealand Flax Phormium tenax, a much taller plant with stouter leaves. Note that the flowers are deep red in colour and the petal tips are not as strongly recurved at the mouth.

Bamboos have progressively become quite a growth industry (excuse the pun!) and some of these large grasses certainly have a proven track record for potentially being aggressive growers and becoming invasive. Thus, recording of plants found outside of parks and gardens is a useful practice that could provide some good data for the future. It doesn't seem all that long ago when pretty much every bamboo you found was going to be Arrow Bamboo Pseudosasa japonica, which was handy because bamboos can be notoriously difficult to identify! Increasingly, however, bamboos have been marketed as the 'must have' accessory for the garden and other species are now to be expected and need to be taken into consideration. On the outskirts of Cromer this week, I found an interesting assemblage of plants on some untended, rough ground that had clearly been planted by someone in the past but which showed no recent signs of cultivation. Among the hotch potch of plants was a couple of bamboos, so it was time for a full suite of photos and some research back home. This one eventually gave itself up as Umbrella Bamboo Fargesia murielae, the first time I have found this one while out and about with my recording sheets.

A closer look at the amazingly polished, rich olive-green stems of Umbrella Bamboo. The leaves are distinctive, too, with their very long, drawn out tips.

Growing not far from the Umbrella Bamboo was another species of this distinctive group of plants. Luckily, this one had stems like polished ebony and it was soon clear that this is Black Bamboo Phyllostachys nigra and another species I have not come across outside of gardens before. Things are clearly changing in our world and getting out and recording that change continues to be an integral and important part in understanding what is going on and how to accommodate it.

As part of the suite of photos that I take of bamboos to assist identification, I always photograph a leaf while holding it up to the light. The number and arrangement of veins in the leaf can be useful in the identification process, but this shot of Black Bamboo also offers a nice, arty finish to this post!

Going Urban - part 1

 A couple of days ago, I had to venture 'into town', something we're avoiding as much as possible at the moment due to the current pandemic and lockdown restrictions. The car was due for its annual MOT and while it was being serviced, I had to kick my heels somewhere - so some urban botany seemed in order and provided a good way to steer clear of any other people that might be about, since everyone avoids the geek staring at the ground and writing things down!!

It's amazing to think that we are now at the start of recording for the next national plant atlas that typically involves 20 years of recording between publications. So it's a great opportunity to get into a variety of habitats and see what's changed. I like urban botanising for two reasons; firstly, it's great fun to see which plant species have found a way to wedge a seed into a crack in a wall or pavement and become the latest plant to conquer new territory. Secondly, our changing climate is seeing an increasing number of introduced plant species from typically warmer climes starting to survive our winters and it's interesting to see just what is out there and can now be recorded as surviving in the environment. In this post, I'll cover the first of these two reasons - plants in cracks!

For me, one of the most amazing thing about plants is their ability - collectively - to be able to colonise seemingly anywhere and this is perhaps never more clear than when we find plants in 'our' urban environments. Any little crack in a wall or pavement seems fair game for a plant's seed to get a hold. If a little bit of organic detritus can find its way in there to act as a growing medium, then even better. As walls age, the mortar begins to crumble between the bricks or stones and it's not long before plants start to appear as part of the 'back to nature' process of decay. Norfolk's coastal towns mostly grew up during the recreational boom years of the Victorian era and the design of buildings from that period seems particularly to offer up some lovely nooks and crannies, while the much older walls of churches in the region - most of which date from the 15th century back to occasionally as early as the 11th or 12th Centuries - are especially favoured by ferns. Here's a picture essay of some photos from my jaunt around Cromer this week, along with some photos from earlier years that illustrate how plants find their way into our lives while our backs are turned!

Seeds from a great variety of plants waft around, either in the air if they are light and furnished with hairs or 'wings' to aid wind dispersal, or along the ground. These seeds tumble around until they fall into a crack where, provided they are not found by hungry birds or invertebrates, the may germinate. We often have an all too thorough attitude to 'tidying up' the streets and as a society we often see these little colonisers as simply weeds, that are getting in the way.

For me, this photo represents the 'Classic Coastal Duo'... Seaside Fleabane (Erigeron glaucus) and Sweet Alison (Lobularia maritima) are plentiful in coastal areas in Norfolk and both originated as garden escapes, with Sweet Alison brought here from the Mediterranean and the fleabane being native to South Africa.

Walls offer both very dry and damp environments and the two habitats attract different plant species. This damp corner on the north side of Alby church presents a classic scene where water runs down from a broken guttering. Mosses soon colonise and provide even better seedbeds as Common Ivy (Hedera helix) takes hold and Tutsan (Hypericum andorsaemum) and Hart's-tongue Fern find little niches.

Ferns are great colonisers of shady walls as they relish the growing conditions and have minuscule spores that waft high on the wind and readily find tiny cracks in walls. In Norfolk, Intermediate Polypody (Polypodium interjectum) is plentiful in such places, such as on this roadside wall at Hunworth.

One of our great colonisers of church walls is Black Spleenwort (Asplenium adiantum-nigrum), here seen on Belaugh church. This plant is plentiful in many parts of Norfolk, yet I have only once seen it growing anywhere other than a church wall! The lime within the mortar makes such places ideal for ferns that would otherwise be plants of limestone outcrops - a habitat that we don't have in East Anglia.

Another plant that seems almost always to be growing from a wall is Trailing Bellflower (Campanula poscharskyana), a plant that naturally grows in limestone hills in the Balkans. It is now well and truly established in towns and cities throughout East Anglia and this plant was found along Cabbell Road in Cromer this week. Later in the year it will have bright blue, star-shaped flowers. 

Some of our native plants are so strongly associated with growing on walls that they have even acquired the habit as part of their name! This photo shows the rock-hugging duo of Wall Speedwell (Veronica arvensis) on the left and Wall Lettuce (Lactuca muralis). The scientific name of the latter even alludes to its love of wall (muralis, as in mural). The speedwell is also a common plant of dry, cultivated or disturbed land and the lettuce can also be found on shady woodland paths.

A number of botanists have built up lists of the plants that they have found growing from walls and it seems that almost anything is possible! Here, a Primrose (Primula vulgaris) grows from the churchyard wall at Matlaske.

Even a Foxglove (Digitalis purpurea) gets in on the habit! Here, on the church wall at Irstead.

Plants that produce heavy berries might seem unlikely candidates to turn up on walls, since surely their seeds would not find their way up there on their own? Indeed so, but berries are eaten by birds and birds regularly stop off on the top of  walls for a quick poop! This church wall at Sprowston has the native Barren Strawberry (Potentilla sterilis) and an introduced Darwin's Barberry (Berberis darwinii) growing out of it, both probably there thanks to the intervention of birds.

Another one from Cabbell Road in Cromer this week is this Hedge Veronica (Veronica x franciscana), one of the shrubby Hebes and one that is commonly grown close to the coast, where it is very tolerant of the salty and wndswept conditions. This species is becoming quite regular as a small seedling in walls and pavements, but plants are often tidied away before they get too large, which is probably reasonable enough since such woody species could eventually damage the structure they are on as they continue to grow. To the left of the Veronica is Pellitory-of-the-wall (Parietaria judaica), another classic wall plant as you might tell from the name and very common in East Anglia.

And on a theme of 'anything seems possible', this germinating Annual Sunflower (Helianthus annuus) seed was a surprise find on a wall in Wells-next-the-sea back in December 2019. Clearly this chunky seed has a story to tell about how it got there, but my money is on it having been tucked into the moss by an industrious Coal Tit, making provisions for the winter.

Moving away from basic walls, the stair wells leading down to basement flats in many coastal Victorian buildings seem absolutely purpose built for ferns. Damp and shady for most of the day, they offer surrogate river cliff habitat. This one in Cringleford is home to a substantial colony of Hart's-tongue Fern (Asplenium scolopendrium).

Of course, one has to keep an eye on plants and woody perennials that can grow into sizeable trees or shrubs are not ideal in such situations. This building in Norwich has a cracked down pipe that has clearly been leaking for years judging by the fine collection of mosses and algae on the wall, but the bristling colony of Common Butterfly-bushes (Buddleja davidii) is a nightmare waiting to happen for someone in the not too distant future!

Anywhere can be fair game as a starting point for plants and surprise finds are far from limited to walls. This Hydrangea (Hydrangea macrophylla) was a bizarre sight as it poked out of a roadside storm drain in Knapton a while ago. How it got there and how it is surviving I'm not sure. It seems unlikely to have come from seed so perhaps it was a small, discarded plant that already had a few roots developed and found itself dropping into a lovely, muddy hollow!

Perhaps taking the prize so far for 'Plant growing in the weirdest place' is this Petty Spurge (Euphorbia peplus) that has germinated from amongst the bristles of the brush that is supposed to be the one I use to clean the car. Perhaps it tells you something about how often I clean the car, then!

In Part 2, we'll have a look at some of the more recent colonists that are turning up and providing us with some head-scratching moments as the latest 'garden escape' from some far flung corner of the globe pops up unexpectedly...