London Plane

Basic Information
Tree ID: 
62
Family: 
Platanaceae
Genus and species: 
Platanus x acerifolia
Description: 
This gigantic London Plane tree sits on the corner of Mansfield and Woodland, just a few blocks up from Ingalls Rink. Its beautiful green bark and rich texture provide this residential area with a touch of nature. Intertwined with the power lines that run parallel to the street, its bare branches reach over 50 feet high, which is slightly smaller than the average height of 60-100 feet tall. This tree's habitat is commonly urban, which allows this London Plane to reside comfortably on the outskirts of the bustling city of New Haven. Its branches have been barren for quite some time due to the winter season, but the multicolored, camouflage-patterned bark is a year-round spectacle.
Surveyors: 
Katherine Werner and Brittani Steinberg
Location
Area: 
Prospect and Sachem
Collected Data
Tree shape: 
Upright pyramidal to upright oval in youth, becomes irregular and spreading with age
Date of tree entry: 
02/07/2017
Height: 
15.90 m
Diameter at breast height: 
1.03 m

Bark
The London Plane's bark is pale gray-green with a rough, flaky texture that exfoliates making the tree look like it is covered in military camouflage. The tree has the camouflage pattern because its bark breaks away in large flakes to help the tree cleanse itself of pollutants.
Twigs & branches
As can be seen here, the tree shape is spreading with branches growing higher up on the trunk and occurring in an alternating arrangement. The London Plane typically grows anywhere from 66-98 feet in height but can get up to 131 feet tall!
Foilage
The leaves of the London Plane are alternate, simple, lobed (3 to 5 lobes), ovate, palmate/pinnate, with each leaf blade tending to be 6-7 inches wide. The medium to dark green young leaves in spring are coated with tiny, fine, stiff hairs that wear off by the late summer. In autumn, the London Plane's leaves turns a yellow-brown.
Reproductive Structures
The London Plane is monecious, meaning that its flowers are unisexual but that both male and female flowers occur on the same tree, usually on separate stems. The flowers appear in small spherical clusters around April, with the male flowers appearing yellow in color and the female flowers appearing red in color. Around October, the female flowers mature into fuzzy, spherical fruiting balls that ripen and survive until early winter when the cluster breaks up and release 2-3 mm seeds.
Fruit
Each fruiting ball, about 2-3 cm in diameter, is composed of numerous, tightly packed cluster of seeds. These seeds have stiff hairs on them that aid in wind dispersal. Often 2 or 3 balls are borne on each stalk. As the fall progresses, the fruiting balls gradually disintegrage and release numerous 2-3 mm seeds.
Seasons
  • Spring (April)
  • Summer (July). Image obatined from Oregon State University
  • Fall (October). Image obatined from Oregon State University
  • Winter (February)
Research
Natural range of distribution: 
Habitat: 
The London Plane can live in a wide range of habitats in many temperate climates. It grows best in hardiness zones 5-9 (as shown in the picture in the natural range of distribution section). It grows in moderate climates all over the world, and grows rampantly in North & South America, Australia, and Europe. Importantly, it can withstand pollution, allowing it to thrive in urban communities, which makes it almost exclusively planted in urban locations. It was widely planted in London, and now this tree makes up over half of the trees in the city. The London Plane also accounts for around 10% of the trees in New York City. This tree particularly enjoys hot summers and heaps of sunlight, but can also withstand cold winters.
Origin, history, and uses: 

The London Plane is thought to be a hybrid of P. orientalis and P. occidentalis. This tree would not be in existence had it not been for colonization, because the two species of trees that cross to make the London Plane were separated by an ocean. The London Plane was first noted in London in the 17th Century by John Tradescant the Younger in his garden in Vauxhall, London. It is plausible this was the first occurrence of this species of tree, as both the parent trees resided in this Vauxhall garden. After its discovery, this tree became very popular and many tree-enthusiasts in London began to plant it. In fact, two London Plane trees were offered as a gift in the 1660s to the Bishop of Lincoln. These trees are still living and growing today, and they can be found at Buckden Towers, Cambridgeshire. 

In the 18th Century, this tree became widely planted along the streets of London as the Industrial Revolution was in full swing. The choice of this tree was obvious: the tree could survive the massive amounts of soot and smoke produced by the new machinery and technology. Additionally, the population was expanding greatly, and urban planning needed to be reconsidered. The strength of the London Plane allowed it to become the most common tree in London, and some of these trees are still alive today. The tree thought to be the oldest resides in central London’s Berkeley Square, presumed to be planted in 1789.

The major use of the London Plane tree is for planting in urban environments. Though the tree is more widely used in its living form, its wood can be used for a variety of other purposes, such as veneer, plywood, flooring, furniture, interior trim, carvings, and other small specialty wood objects.

Phenology: 
Flowering occurs in the spring, and can be described as a short and intense process during April and May in the Northern Hemisphere and September and October in the Southern Hemisphere. Leaves begin to grow when the weather gets warmer in the months preceding the flowering. In the autumnal season, the leaves begin to change colors. They fall off during the winter, as this tree is deciduous. Higher temperatures promote earlier flowering and fruiting. Due to the colder spring season of this past year, our tree has yet to reach this stage in its phenological cycle.
References: 

Breen, Patrick (2017). Platanus x acerifolia. Landscape Plants. Oregon State University. http://landscapeplants.oregonstate.edu/plants/platanus-acerifolia

Factsheet on London Plane from University of Florida:  http://edis.ifas.ufl.edu/st488

Hull, Robin. A Short Guide to the London Plane. http://www.treetree.co.uk/treetree_downloads/The_London_Plane.pdf

London Plane information page from University of Connecticut:http://www.hort.uconn.edu/plants/detail.php?pid=335

National Arbor Day Foundation Tree Guide: https://www.arborday.org/trees/treeguide/TreeDetail.cfm?ItemID=904

The Morton Arboretum: http://www.mortonarb.org/trees-plants/tree-plant-descriptions/london-planetree

Canadian Tree Tours: http://www.canadiantreetours.org/species-pages/London_plane-tree.html

The Wood Database: http://www.wood-database.com/london-plane/

Patrick, Charlotte; Elaine, Lui Yi Ling; Eley, Mark; Lin, Meng-Hsuan. The London Plane Tree (Platanus x acerifolia) as a climate change indicator species in Australia. Cygnus (2012) 1:112-122.

Venables, Ben. ​The Secret History of the London Plane Tree. http://londonist.com/2015/03/the-secret-history-of-the-london-plane-tree

More
Other information of interest: 

Allergy-sufferers, beware!

The spores released by the fruit of this tree can cause major problems for those with asthma and allergies. Inhaling the short hairs present on the leaves and seeds can obstruct the breathing pathway and cause irritation for those with preexisting breathing problems.

Media and Arts
Disease threatens to wipe out London's plane trees

A London Plane Tree

By Amy Levy 

Green is the plane-tree in the square,

The other trees are brown;

They droop and pine for country air;

The plane-tree loves the town.

Here from my garret-pane, I mark

The plane-tree bud and blow,

Shed her recuperative bark,

And spread her shade below.

Among her branches, in and out,

The city breezes play;

The dun fog wraps her round about;

Above, the smoke curls grey.

Others the country take for choice,

And hold the town in scorn;

But she has listened to the voice

On city breezes borne.

https://www.poemhunter.com/poem/a-march-day-in-london/#content 

Comments

Brittani Steinberg on April 24, 2017:
Katherine Werner on April 24, 2017: