Plane trees of London

The plane tree cultivar 'Palmata'

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In this page, quotations from other works are written in italics and within single quotes. Botanic names are in italics. Cultivar names are written within single quotes, but are otherwise in plain text.

Summary

This account considers some references from the 19th century to a cultivar of plane tree named 'Palmata'. It discusses whether any specimen of this cultivar is likely to be found now in London and describes some likely contenders. It considers how far they match the known descriptions of 'Palmata', and identifies one clone of London's plane trees as the most likely match to the original references.

Sources and description

The key descriptions of the cultivar are in two articles in the Gardener's Chronicle from the 1860's. The first (see reference to Rivers, 1860) is an article by Thomas Rivers of the Sawbridgeworth Nurseries, and the second article (see reference to 'Platanus', 1866) is anonymous, but also likely to be by him. The two articles also describe briefly some of the other varieties of the plane trees then grown in the capital. Some of the trees they describe are likely to have been young specimens of the mature trees that we see now. Four varieties are described in the first of these articles, there named 'Platanus acerifolia palmata', 'Platanus acerifolia palmata superba', 'Platanus acerifolia pyramidata' and 'Platanus acerifolia grandifolia'. Some of these are discussed again in the second article, together with the Oriental plane. Only the tree described under the first of these names is discussed here.

Based on the above articles, the tree can be described as follows. It has palmate leaves that are more deeply lobed than most hybrid planes, and are similar in lobing to those of the Oriental plane. The young leaves and buds are covered in thick fawny down. The leaves are thick and resistant to wind damage, and remain green and on the trees late into autumn. The young tree is vigorous and hardy, and growth is more upright than in the Oriental plane. The bark does not flake off to the same extent as on other planes.

Although the descriptions are sketchy, additional details can be deduced from the articles and their context. In particular, the 1866 article, which is probably by Rivers (see notes) says that the trees were sent from the Sawbridgeworth Nurseries to Kew Gardens. Given the interest that Rivers took in this cultivar, and given that he owned a major nursery, it is likely that he distributed this tree more widely. At least some of the trees to be found in London today should therefore be of this form.

Existing varieties now found in London

Many cultivars of Platanus x acerifolia can be found now in London. Three of these, the common cultivar 'London', the equally common 'Pyramidalis' and the infrequently found 'Augustine Henry' do not resemble the tree considered here. Apart from these, there are at least two distinct varieties among the capital's mature trees that are often found in inner London. Based largely on the locations where I first observed them, I have previously called them 'Hackney' and 'Westminster' (in previous versions of this website, I called them the 'Hackney Form' and the 'Westminster Form'). Despite the names, they can be found in moderate numbers over most of inner London, and occasionally in other places. Below I try to show that 'Palmata' is most likely to be the clone that I called 'Hackney', and I also consider the possibility that it may be 'Westminster'.

Matching 'Palmata' to Hackney

Outline of leaf

Foliage of 'Hackney'

The form that I have called 'Hackney' is described in detail on this page at this website. In foliage, bark, growth habit and fruiting, it is clearly different from the other forms, so that it would be surprising if the differences had not been noted before. While it appears to be a single clone, there are some trees which have been sometimes seen with anomalous features, though these may well be due to the location and the local growing conditions. I have previously assumed from its fruits (up to five can sometimes be seen on a single stem) and from its deep cut leaves that it is a variety of the oriental plane. This assumption has also been made by others. However, as it seems to be infertile and because the fruits are unusually large for an Oriental plane, it seems possible that it is one of the hybrid planes.

Some specific descriptive phrases about 'Palmata' by Rivers are given below in italics, with an account of how they correspond to characteristics of the cultivar 'Hackney'.

Another descriptive phrase from Rivers is that it is 'a very straight-stemmed vigorous grower'. This is quite difficult to assess now, since the trees that being considered are all mature with no young specimens to be considered. Most have straight stems but whether these are due to formative pruning or to their natural growth cannot be seen. The vigour of their vegetative growth is now moderated in today's mature trees by their heavy fruiting. Rivers does not mention the fruit of 'Palmata', so the trees he described may not have reached fruiting size.

There are two statements by Rivers which do not appear to agree with 'Hackney' as seen today; these are listed below, with possible explanations.

Rivers also said of 'Palmata' that 'it has been ... sent from the Sawbridgeworth nurseries some years ago to Kew'. The form 'Hackney' can be found at Kew now, though the location of the trees of this type that I know of is not in today's enclosed grounds. They are by the side of Ferry Road, by the Thames Towpath and alongside the approach road to the Brentford car park, an area that I believe belongs to the Royal Botanic Gardens. The trees there are recorded by the botanic gardens and bear their labelling. There is also one damaged and unhappy looking tree of this form nearby beside the roadside kerb on Kew Green, to the southeast of the Herbarium. It is possible that there are other trees of this clone elsewhere in the grounds.

Rivers also mentions large trees at Audley End. These can be seen there now, in large groups scattered around the parkland, and distinctly larger than the trees in London.

Distribution, size and age of 'Hackney'

The locations, sizes, and distribution of the trees of the form 'Hackney' within London are consistent with them having been planted in a few decades, probably between 1860 and 1890.

The majority of the 'Hackney' trees are found in inner London, within the area that was built up by the later decades of the 19th century. Numbers can be found in the central London Royal Parks, in the principal early metropolitan parks including Southwark Park, Victoria Park, and Finsbury Park. Few are found outside this area. When they are found outside inner London, then as at Kew, they are in areas that would have been urbanised by the end of the 19th century or otherwise been locations for ornamental trees.

The sizes of the tree are in general slightly smaller than those of other clones of plane trees to be found near them. As mentioned above, I believe that this can be explained by their heavy fruiting, and hence a reduced rate of vegetative growth compared with other planes. No young trees are known to the author. Neither are any of the trees especially old, judging by their size. A possible reason for this age distribution is that they may be difficult to propagate by cuttings, the normal method used for plane trees. Not only would this explain why their distribution stopped, but grafting on to rootstocks of other clones would also account for the change in trunk shape often seen at the base of their trunks.

At Southwark Park (opened in 1869) they can be found in the avenues, but mixed with other planes. A possible explanation is that they were obtained as replacements for losses among the early planting.

Rivers makes reference to some trees outside London, including at Audley End, south of Cambridge. These can be seen today, and they are indeed distinctly larger than any of those that in London, which fits in with being mature when he saw them.

Other possible matches

Leaves of Westminster

Foliage of 'Westminster'

The description should be compared to other possible matches. Of the trees that are regularly found in London, only one appears to be a likely contender. This is the clone 'Westminster'. It fails on some of the key tests; its leaves do not resemble the Oriental plane, though sometimes they can be rather more deep lobed than the common London plane. Its young leaves are not distinctively downy. However, it has two characteristics that match those of River's description. The first is that it often has green leaves much longer in autumn compared to other planes. This can be seen to be on younger late summer growth which this tree regularly produces, and similar green autumn foliage can be seen on other trees that produce late summer growth such as on pollarded trees. Hence this characteristic can be considered one associated with the tree's growth pattern, and one that is likely to occur in 'Hackney' as well if and when it produces later summer growth. The second characteristic is that on on the trunks of older trees the bark peels relatively little. It instead remains on the tree to become thick and fissured. This is not seen on younger and smaller branches, where the bark is usually shed. This sometimes is shed in small plates in a manner similar to that of 'Hackney', though not at the same thickness. Since the shedding of bark is thought to result from lack of flexibility in the bark to accommodate changes in girth, the persistence and thickening may be related to the lack of change in the relative radial dimension of the main trunk. On the whole it seems unlikely that this tree can be that described by Rivers.

Conclusion

I therefore offer the possibility that this clone, that I called Platanus orientalis 'Hackney', is actually the tree that Thomas Rivers called 'Platanus acerifolia palmata'. Specifically, I think it is likely that;



Notes

1. The name 'Palmata' is used here as a cultivar name, as also used by Rivers. The oriental plane was called Platanus palmata by Conrad Moench, but this is not the same usage.

2. Of the two articles in the Gardener's Chronicle, the first is signed 'Thos. Rivers', and the second is signed 'Platanus'. Judging from the content, and from the style of writing, both are by the same author, who is probably the 3rd Thomas Rivers (who died in 1877), of the Sawbridgeworth Nurseries, Sawbridgeworth, Hertfordshire. The fact that the second article was published under a pseudonym can be explained by his criticisms and digs within it of 'the planting functionaries of the government', who were probably also important to him as customers of his business.

3. The trees by Ferry Lane, by the entrance to the car park at the Brentford Gate to Kew Gardens, are recorded by the Gardens. The labels describe them as Platanus x hispanica, and the accession records state that they were supplied by 'Belwood Nurseries Ltd.'. I have been unable to trace this nursery; as far as I can determine, there is no trace of such a nursery other than the modern Bellwood Trees in Perthshire, which is unlikely to have been a supplier of plane trees in the 19th century.

4. In Bean's Trees and Shrubs Hardy in the British Isles, there is reference made to the articles by Rivers. The trees were not known to the author, and no further detail is offered on the cultivar. However it does make reference to two trees at Kew which may be worth further attention. One is by the 'south-east corner of the Herbarium'; the second is 'north of the planting around King William's Temple'. The first tree appears to be no longer present, and the second is certainly distinctive but is a glossy leaved form of a type not often seen elsewhere. Bean's Manual also says that a plane under the same name 'Palmata' was sold by Barron's Nursery, Derbyshire in the 19th century.

Specimen trees

Trees of both clones can be found all over inner London, with a few further out. Some specimens of the 'Hackney' clone are listed below, using their latitude-longitude coordinates.

References

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26-February-2020