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BOSTON IVY

Parthenocissus tricuspidata

Vine Family [Vitaceae]

month8sep month8sept month8oct month8nov

Berries: berryZpossible        berryZgreen berryZyellow berryZbluish berryZblack  (5-10mmφ, poisonous)
berry8oct berry8nov berry8dec

category
category8Climbers
status
statusZneophyte
flower
flower8green
 
flower
flower8cream
 
inner
inner8brown
 
morph
morph8actino
 
petals
petalsZ5
petals
stem
stem8round
 
toxicity
toxicityZmedium
 

19th June 2013, a pub wall, Wheelton, Lancs. Photo: © RWD
Unlike plants in the same Parthenocissus family, Virginia-Creeper and False Virginia-Creeper with their palmate 5-lobed leaves, Boston Ivy has either simple leaves or 3-lobed leaves. This woody vine can climb walls and trees up to a height of 30m.


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
These leaves seem to be slightly smaller and a slightly different shape (but still 3-lobed) to the previous examples. It is growing up a brick wall. However, the size specification for Boston Ivy leaves is 5cm to 22cm, so all should be well.


31st Aug 2018, a garden wall, Hillside, Sefton Coast. Photo: © RWD
Leaf size can vary enormously on some specimens (they might be differing cultivations?).


11th June 2014, a wall, Bradwell, Derbyshire. Photo: © RWD
It attaches to the substrate by means of sticky pads which are on the ends of each branch of the tendrils.


11th June 2014, a wall, Bradwell, Derbyshire. Photo: © RWD
The leaves have a glossy upper surface and are a bright-green, but redden easily in strong sun.


31st Aug 2018, a garden wall, Hillside, Sefton Coast. Photo: © RWD
Clinging on to the coarse bricks. They can be red-edged, or suffused with red.


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
Here some leaves have turned a bright crimson colour.


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD


31st Aug 2018, a garden wall, Hillside, Sefton Coast. Photo: © RWD
Leaves on long stalks all emerging close together from woody stems.


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
The flowers are tiny (compare the leaf on the left). The network of branches and tendril can be seen close to the brickwork behind.


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
The flowers nominally have 5 petals although some here have but 4.


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
The 5 petals are pale-green. Long stamens lie along the same radial axis as the petals, each tipped by a cream-coloured anther.


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
The ovary in the centre is paler-green, slightly 5-lobed and tapers to a round neck, a bit like a laboratory flask or vinegar bottle for the dinner table. Unopened flower bud just right and below centre.


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
The pale green petals have in-curled irregular white margins, reflecting the shape of the flower-bud.


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD


31st Aug 2018, a garden wall, Hillside, Sefton Coast. Photo: © RWD
Sepal cups cupping the petals; the flowers are stalklessly attached to stems by a greener sepal cup.. Petals and filaments withered brown or dropped off on topmost flower


10th Sept 2014, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
The stems are stubby and branched. The flower is borne within a darker-green stubby golf-tee thingamajig (to be technical) aka the sepal cup :-)


31st Aug 2018, a garden wall, Hillside, Sefton Coast. Photo: © RWD
An opened flower, 5 cupped petals with 5 pale green filaments holding large cream-coloured pollen-laden anthers. A developing ovary in the centre which is a more yellowish-green.
The ovary from the side (bottom) - the conical sepal cup now has a gap where once the petals were before dropping off as the ovary matures.


31st Aug 2018, a garden wall, Hillside, Sefton Coast. Photo: © RWD
The developing ovaries atop the sepal cup. The stigma is the (here reddish) disc atop the short stubby style on the ovary.


31st Aug 2018, a garden wall, Hillside, Sefton Coast. Photo: © RWD
As yet unopened flowers. Sepal cup cupping the 5 petals still neatly mitred together at the top.


11th June 2014, a wall, Bradwell, Derbyshire. Photo: © RWD
A new shoot with leaves of various stages of growth is sprouting tendrils near the end.


11th June 2014, a wall, Bradwell, Derbyshire. Photo: © RWD
Presumably the ovaloidal green tips on the tendril will eventually develop into sticky discs which will attach themselves to the vertical substrate, enabling the plant to reach 30m in height without getting dizzy spells.


31st Aug 2018, a garden wall, Hillside, Sefton Coast. Photo: © RWD
Red discs (not fawn-coloured dead ones) have attached themselves very firmly to the brickwork. The tendrils leading to the discs are branched.


31st Aug 2018, a garden wall, Hillside, Sefton Coast. Photo: © RWD
Close-up of discs


6th March 2017, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
Early in the year when all foliage and inflorescences have gone the tendrils are far easier to see. Pulling these plants off the wall will inevitably lead to damage of the wall; such is their tenacity. If removal becomes necessary (these plants are notoriously voracious spreaders), then kill the plant first by severing the trunks descending into the ground, leaving for a few weeks for the plant to die before removing. This will limit the damage caused. These specimens look brown, black and dead, both stems and discs.


6th March 2017, a garden wall, Freshfield, Sefton Coast. Photo: © RWD
Although most look as if they are dead.


Not to be semantically confused with : Ivy (Hedera helix) [a plant with similar name belonging to the Araliaceae, a totally differing family]

Many similarities to : Virginia-Creeper (Parthenocissus quinquefolia) and False Virginia-Creeper (Parthenocissus inserta) which belong to the same Vitaceae family but have leaves that are usually 5-lobed. False Virginia-Creeper lacks the sticky discoidal terminations on the ends of the tendril possessed both by Boston Ivy and Virginia-Creeper.

It is a neophyte, grown on tall walls and escapes into the wild to grow in hedges, shrub and old walls. It is very scattered in the British Isles, mostly in the North to the South West. It is native to Eastern Asia such as japan, Korea and parts of China.

The fruit is bluish-black and a little like a grape, but much smaller, 5 to 10mm across. It is poisonous, containing Oxalic Acid in the form of raphides, very thin needle-like crystals able to easily penetrate individual cells and cause their demise. It is thus a physical poison, rather than a chemical poison.


  Parthenocissus tricuspidata  ⇐ Global Aspect ⇒ Vitaceae  

Distribution
 family8Vine family8Vitaceae

 BSBI maps
genus8Parthenocissus
Parthenocissus
(Virginia-Creepers)

BOSTON IVY

Parthenocissus tricuspidata

Vine Family [Vitaceae]