A mistletoe find...

[alindsay]

I didn't expect to see a bunch of mistletoe growing in a Rowan tree on a very urban street full of car pollution. However it looked healthy with quite a lot of berries.

Is there any tree it will not grow on?

A welcome sight anyway ...

[Dorts]

Mistletoe - Viscum album, is mainly found on members of the Rose Family such as Apple, Thorn, Rowan etc. Also Ash, Birch, Lime and Poplar are often host's. It very rarely grows on Oak, and I have never seen it on Beech.
But in Britain Apple has always been its prefered host tree.
Dorts.

[alindsay]

Thanks Dorts

[The Woodman]

I've recorded it on Hazel, Rowan, Lime, Poplar, Birch, Hawthorn, Apple and Scots Pine in Switzerland.

[Dorts]

One of my sons lives in the Périgord region in France. Poplars of various species are particularly common along the roadsides there , and in some places virtually every tree is completely covered in mistletoe. I was quite amazed at the amount when I first saw it, quite a spectacle.

Unfortunately here, so many of our old apple orchards have been removed, along with the mistletoe, in favour of smaller, younger (Mistletoe-free) orchards so that it has now become quite scarce.
Dorts.

[poschiavanus]

It's extremely common on Rowan in an '80s estate I know in Berkshire: although sadly people are removing some of the trees now.

Another commonish host is False Acacia/Black Locust Robinia pseudoacacia: I noticed one with mistletoe growing in a supermarket car-park in November at Burton Joyce in Notts, but its pretty common on this host in Berkshire (e.g., Knowl Green on the A4 between Twyford and Maidenhead).

Last year I passed through the Nottinghamshire village of Winnkburn, and was amazed how much mistletoe was growing (it's a fairly scarce plant in the county). Consulting the county flora revealed that this peculiar outlying patch of mistletoe country has existed for a while: "Winkburn, everywhere, on thorn, lime, elm, poplar and crab;" (Howitt, 1963: p. 169).

The subspecies (possibly a distinct species, V. laxum) on conifers (pines & spruces) is extremely common in the woods between Briancon and Montgenevre in the French Alps.

The limit for intensive infestation of Poplar plantations passes through the Swiss Mittelland somewhere near Freiburg/Fribourg. I remember a Swiss friend remarking on the appearance of mistletoe whilst driving along the motorways from Zurich to Geneva.

[Dorts]

Posch. It's interesting you mentioned Elm. I omitted it from my brief list of host trees due to its absence as a mature tree in most of the country.
When Elm was common, it was occasionally to be seen with mistletoe among its branches.
I have never seen a complete list of host species, but imagine it would contain a few surprises, such as your Robinia, which is a new one to me.
Dorts.

[poschiavanus]

Originally Posted by Dorts

Posch. It's interesting you mentioned Elm. I omitted it from my brief list of host trees due to its absence as a mature tree in most of the country.
When Elm was common, it was occasionally to be seen with mistletoe among its branches.

Howitt was writing before Dutch Elm disease: when I drove through the village it was at dusk and the obvious host were mature parkland Limes.

I have never seen a complete list of host species, but imagine it would contain a few surprises, such as your Robinia, which is a new one to me.
Dorts.

A quote from an Irish Times article about mistletoe growing in Glasnevin Botanical Garden :

"including apple trees (the plant is traditionally associated with orchards), maples, robinias, davidias, limes, crataegus, sorbus, poplars and even betulas"

(found via Jonathan Brigg's Mistletoe Diary).

And from Michael Crawley's Flora of Berkshire

"The usual host plant is Tilia x europaea in Berkshire, and where it is abundant, the parasite can fill the entire inner volume of the canopy. Large tress can support more than 100 mistletoe individuals. In the Queen’s garden at Frogmore, the abundance of mistletoe and the range of host plants is the greatest I have seen anywhere: Robinia pseudoacacia, Salix alba, Quercus rubra, Juglans nigra, Tilia cordata, Populus alba, P. ‘Robusta’, P. x canadensis, Syringa vulgaris, Betula pendula, Acer rubrum, A. saccharinum, and various ornamental cultivars of Malus, Prunus and Crataegus are all hosts. Although Quercus robur is a frequent host of mistletoes in continental Europe, there are no Berkshire records. I have only once seen mistletoe on Sorbus aria in Berkshire (at Hall Place, Burchett’s Green; see below)."

Jonathan Brigg's recent article in British Wildlife (23 (2), pp 23-31) gives a histogram of hosts from the national survey undertaken in the 1990s.

To finish, a couple of pictures of mistletoe in Rowans:

[aeshna5]

I was surprised to find Mistletoe in a garden Robinia in Barnes, south-west London a few years back + is still there.

[jonathanbriggs]

Originally Posted by alindsay

I didn't expect to see a bunch of mistletoe growing in a Rowan tree on a very urban street full of car pollution. However it looked healthy with quite a lot of berries.

Is there any tree it will not grow on?

Just been made aware of this thread through the link back to my Mistletoe Diary above

As others have pointed out above, Viscum album will grow on a very wide range of hosts. Though to be specific this wide host range really only applies to our subspecies of Viscum album (now V. a. album but used to be V. a. platyspermum). This can grow on many hundreds of host taxa across its native range (Europe across into Asia), and quite a lot more if you include garden cultivars etc. It is considered to have the largest host range of all the mistletoes (1500 ish mistletoe spp worldwide). Curiously the other Viscum album subspecies (2-3 in central Europe) are very host-specific.

Rowan is a fairly frequent host wherever V.a. album can find it - which is usually in suburban situations. Other Sorbi (whitebeams etc) are regular hosts in 'wild' (cotswold escarpment, wye valley cliffs etc) situations.

Re the car pollution comment - pollution isn't really a big issue for mistletoe as it's not a plant that grows on bark like lichens, bryophytes or other epiphytes - it's growing within the host branch so is not really affected by atmospheric pollution.