Giant Hogweed in the news 2: Mark to the rescue!

Giant Hogweed
Image courtesy of J. Crellin/Floral Images
http://www.floralimages.co.uk/page.php?
taxon=heracleum_mantegazzianum,1

With Giant Hogweed still making the headlines today, BSBI has been working with colleagues in the media and across the botanical community to get some clear and helpful information out about this plant and the level of threat it poses to the public. 

So botanist Dr Mark Spencer (an active BSBI member based at the Natural History Museum) has just filmed an outside broadcast with Joe Tidy for Sky News [now available here, also features Sir David Attenborough - Ed.] and is now hot-footing it to the ITV News Meridian studios for a piece going out on the 6 o'clock news tonight. 

He will be aiming to explain how to identify Giant Hogweed (there are other perfectly benign plants which look superficially similar), where it grows, and whether or not it is increasing. 

Let's hope that once people know what to look out for, they will be able to avoid Giant Hogweed and enjoy the vast majority of wildflowers which are quite safe to touch. All this just goes to show how important it is to be able to identify plants with accuracy and confidence, i.e. to have some botanical skills! 

Pollinator ID for Botanists: an introduction

Pair of mason bees on Charlock Sinapis arvensis.
Female has pollen-collecting hairs beneath the abdomen;
male lacks these hairs & doesn't collect pollen.
Image: R. Clark
 

This is the final day of national Pollinator Awareness Week and many of us who have been out botanising have become very aware of our lack of pollinator ID skills! 

Fortunately BSBI botanist Ryan Clark, who co-ordinates our annual New Year Plant Hunt and sits on BSBI Meetings & Communications Committee, is also an entomologist with a particular passion for pollinators. 

A recent graduate, his BSc dissertation was on using plants to conserve pollinators.

Ryan has very kindly put this guest blogpost together for us:

Pollinator ID for Botanists: an introduction.

Male leafcutter bee, showing
the typical resting position,
with wings outstretched.
Image: R. Clark

With about 87% of the world’s flowering plants relying upon insect pollination to reproduce, pollinators play a vital role in terrestrial ecosystems. 

In 2013, the State of Nature report [to which BSBI was a contributor - Ed.] was launched; the report estimates that over two thirds of our invertebrate species have declined over the last fifty years, including many of the orders of insects that can act as pollinators. 

Approximately 58% of our flowering plant species have also declined over the same time period, with specialist plants and pollinators worst affected. 

In Britain there are a number of groups of insects that can act as pollinators of the plants that we all know and love including bees, hoverflies, moths, butterflies, beetles and other flies. Pollination is accidental from the insects' perspective and most insects, including beetles and wasps, have the capabilities to carry pollen between plants.  

Bees

A female mining bee, showing that this group
collects pollen on the hairs on their hind legs.
Image: R. Clark

Bees are arguably the most important pollinators in Britain and are also the group of pollinators that are most in trouble, facing widespread declines in both population and distribution. 

When people think of bees they often think of the honey bee, an arguably non native species, or bumblebees. Solitary bees, however, are often overlooked and make up around 80% of the 250 bee species found in Britain. 

Honey bees are effective pollinators but only due to the numbers in which they are found in Britain, with bumblebees and solitary bees being much more effective at pollination. 

A hoverfly pretending to be a
bumble-bee! Note how the eyes &
 wings are different from bees.
Image: R. Clark

Like honey bees, bumblebees are social, with colonies, comprising one queen and lots of worker bees (also females), which break down, with new queens and males produced. 

Solitary bees - as the name suggests - usually live alone and collect pollen to provision their own young only and they are smaller than bumblebees. The main types of solitary bees that you are likely to see are miner bees (Andrena species), leafcutter bees (Megachile species) and mason bees (Osmia species), all of which are effective pollinators. 

Miner bees in the genus Andrena nest usually in the ground, digging a tunnel and laying eggs in there, provisioning the young with a mix of nectar and pollen. Most of these bees are rather large and chunky and they collect pollen on their hind legs. 

On the other hand mason bees, Osmia species collect pollen on the underside of their abdomens. Similarly, leafcutter bees also collect pollen on the underside of their abdomens and, with their wings outstretched, are distinctive when at rest . 

For more information on different types of bees in Britain, please follow this link. 

Hoverflies

Marmalade hoverfly on Viper's-bugloss
Echium vulgare
Image: R. Clark

Hoverflies are also rather efficient pollinators and are thought to be undergoing dramatic declines, but we know even less about these declines than we do for bees! There are around 270 hoverfly species found in Britain, nearly all of which visit plants for nectar and therefore carry pollen from one plant to another. 

Hoverflies are best noticed by their hovering action in midair, although this trait is shared with some other fly groups and often mimic bees.Their eyes are different though and they have no way of purposefully carrying pollen on their bodies. Flies also appear to have one pair of wings, whereas bees have two. 

Beetles are also important pollinators:
seen here on Bramble Rubus sp.
Image: R. Clark 

I plan to write a more detailed guide to hoverflies later this week, so keep an eye on my blog here. I should also point out that, although less showy than hoverflies, other fly families are also remarkable pollinators, they are just not studied as well in Britain.

Butterflies and Moths

We are all familiar with butterflies and day flying moths visiting flowers by day and carrying pollen between plants, but what about at night? 

There are a remarkable 2500 species of moth in Britain ranging in size from a few mm long to over 10cm long and they are busy pollinating plants while we sleep. Some plants have even adapted to release scents at night to attract these wonderful insects. Moths are even thought to pollinate some orchids! 

Giant Hogweed in the news

Giant Hogweed in flower
Image courtesy of J. Crellin
http://www.floralimages.co.uk/page.php?
taxon=heracleum_mantegazzianum,1

Barely a day seems to go by without another media report about another incident of somebody having a close (and often painful) encounter with a Giant Hogweed Heracleum mantegazzianum. 

Some of the reports are quite alarming but where has this plant come from, is it on the increase and how dangerous is it?

Ian Denholm, BSBI President, and Kevin Walker, BSBI Head of Science, have been in great demand from journalists asking where Giant Hogweed comes from originally (the Caucasus Mountains), when it was first introduced into Britain & Ireland (first record is from 1817), where and when it was first recorded in the wild (Cambridgeshire, 1828) and whether or not it is increasing.

Fortunately these answers were all at our fingertips, thanks to both the BSBI Distribution Database and New Journal of Botany (NJB), our science journal. 

Giant Hogweed records.
Downloaded 15/7/2015
Courtesy of I. Denholm

Although NJB is only available to BSBI members and subscribers, one of our current 'Editor's Choice' papers is this one about Giant Hogweed, published in 2013 and now available free to view and/or download. 

The paper has lots of info about the plant's history in Britain and about the furanocoumarins (the chemicals responsible for Giant Hogweed's fearsome reputation), which were present in every sample the authors looked at. 

They concluded that the plants "pose a potential threat to the general public and the priority given to their eradication, particularly in amenity areas, should be rated accordingly".

And the BSBI Distribution Database? Click here to see our interactive map for Giant Hogweed: you can zoom in to any 10 x 10km square across Britain and Ireland and see whether the plant has been recorded there in six different date-classes, starting with pre-1930 records and ending with the current date-class, which started in 2010 and closes with Atlas 2020. 

So, is Giant Hogweed increasing? In the map (above left) - the result of Ian interrogating the database earlier today -  each shaded square indicates where the plant is recorded right now. See also this article in The Express which uses a rather snazzy version of our distribution map for Giant Hogweed, giving totals across the decades. 

Giant Hogweed in leaf
Image courtesy of J. Crellin
http://www.floralimages.co.uk/page.php?
taxon=heracleum_mantegazzianum,1

Anyone can zoom in to our distribution maps to a certain extent (and are encouraged to do so!) but if you would like greater access to the latest data, showing which wild plants are growing where and how this is changing, then you will need to join BSBI and get involved in our botanical recording community. 

If you are already a BSBI member, please email Kevin or Alex if you would like to request greater access to the database. 

If you are unsure how to identify Giant Hogweed, there are some helpful pointers on this factsheet by Irish botanist Oisin Duffy or try the Environment Agency's factsheet here. While out botanising, if you encounter a Giant Hogweed, handle with care, don't get burnt and don't forget to check the BSBI database - is the plant recorded in your locality?

If not, please send your record of it to your County Recorder, so we can build up a clearer picture of where Giant Hogweed is growing across Britain and Ireland.

Bees spotted collecting pollen from grass!

Bumblebee (possibly Bombus lucorum
 group), Whitemead, Forest of Dean
27/6/2015. Image: T.C.G. Rich

It's national Pollinator Awareness Week, so here is a bee-related post from BSBI botanist Dr Tim Rich:

"Woken early whilst camping, I sat drinking tea in the quiet of the early morning sunshine. Except it wasn’t quiet, a few bees were buzzing in the unmown grassy strip by the tent. 

"Looking closer, I was very surprised to see the bees were collecting pollen from a grass! Everyone knows grasses are not designed for pollination by bees; they are pollinated by the wind. 

"For about an hour we watched as the bees came and went, systematically visiting meadow foxtail heads. 

"Grasses produce no nectar so presumably the bees were simply after the nutrient-rich pollen for their young. Not many bees, but at least three individuals of a bumblebee and two honeybees were collecting pollen. 

Honeybee Apis mellifera on
Meadow foxtail Alopecurus pratensis,
 Whitemead, Forest of Dean
27/6/2015. Image: T.C.G. Rich

"They selected grass heads with lots of fresh yellow or purple anthers and combed the pale yellow pollen into the pollen sacs on their legs. As they landed on the meadow foxtail heads, the delicate stalks bent over with the extra weight of the bee. 

"They ignored us whilst we tried to take pictures, and also ignored the few buttercups present and other grasses. 

"Grass anthers open in early morning and shed pollen quickly as they dry out, so the bees stopped coming mid morning when the remaining pollen had blown away. 

"Were the bees visiting grasses to collect pollen because they were so desperate for food now that so few flowers are left in the countryside, or have they been doing it for years? 

"Only further observation will tell, but this was no random, one-off event. Two different bee species were taking advantage of an abundant pollen source. There were a few other wild flowers present such as buttercup, bramble, hogweed and elder but none were abundant. 

Unmown grassy strip by tent with few flowers.
Image: T.C.G. Rich

"There are a few reports of bees visiting grasses in the literature and on the internet, but mostly in the tropics, usually of grasses with dense heads with lots of anthers like meadow foxtail which the bees can visit easily. 

"Honey has often been reported to have grass pollen in, but it was usually regarded as incidental but now it may not be".

Further information and images from:

Dr Tim Rich

Botanist

57 Aberdulais Road, Cardiff C F14 2PH

tim_rich@sky.com

07799620035

Tim Rich revisits Attenborough's Hawkweed

Tim and Attenborough's Hawkweed, Cribyn
Image: C. Gait

Last December, the discovery of Attenborough's Hawkweed Hieracium attenboroughianum by botanist and BSBI member Dr Tim Rich went public with a scientific description published in New Journal of Botany and coverage in the wider media.

Now it's summer and last weekend, Tim returned to Cribyn, a National Trust (NT) site, to see "his" - or is it Sir David's? - Hawkweed in flower, with a NT group.

Tim says that Attenborough's Hawkweed was in full bloom, the sun shone and everybody had a lovely afternoon. There are two more images here. 

I couldn't get any more info out of him about the day or the Hawkweed (apart from a brief mention of cake!) This is because Tim has just made another interesting botanical observation, so that's what he wants to talk about right now - more to follow...

New App to help us gather evidence of ozone injury on vegetation.

Visible ozone injury: Bronze stippling 

between leaf veins of Birch Betula pendula

Image: F. Hayes

A small display at last autumn's BSBI Annual Exhibition Meeting introduced 172 BSBI members to a fascinating new project set up by Katrina Sharps and colleagues from the Centre for Ecology & Hydrology (CEH). 

A new ozone smart-phone App has been developed by CEH - it allows incidences of ozone injury on vegetation to be recorded as soon as they are spotted in the field, so this summer Katrina and her team are inviting botanists to try out the App and get involved in a worldwide effort to gather evidence of ozone damage on plants.  

Visible ozone injury: Pale cream spotting on

 White clover Trifolium repens leaves

Image: F. Hayes

Katrina said "While ozone occurs naturally in our atmosphere, additional ozone is formed as a result of human activities, particularly due to vehicle and industrial emissions from fossil fuel burning. 

"Certain weather conditions (warm and sunny) can lead to “ozone episodes,” with concentrations peaking for several days at a time.

"Ozone is a very reactive gas and can negatively affect both humans and plants in a variety of ways. In humans, ozone primarily harms the respiratory system, causing irritation and inflammation in the lungs. 

"Ozone is absorbed via the leaf pores of plants, which can lead to damage in sensitive species. 

"For example, visible injury on the leaf surface, a reduction in growth (e.g. beech, birch, white clover) and reduced quality and quantity of crop yield (e.g. wheat, oilseed rape). 

The upper surface of these Wych elm Ulmus glabra 

leaves shows visible ozone injury while 

there is no damage on the underside of leaves

Image: M.J. Sanz & V. Calatayud

"The hot weather in the UK at the end of June has led to an increased concentration of ozone in our atmosphere, meaning that the coming weeks will be a good time to search for ozone damage on vegetation.

"The easiest way to detect ozone damage on plants is to look for evidence of visible injury on the leaves. 

"While symptoms can vary between plant species, there are several diagnostic features that tend to be commonly found in ozone-damaged plants: 

Visible ozone injury: Older leaves on
this Rum cherry Prunus serotina
are more damaged than younger leaves
 Image: M. Schaub

1) Small, pale yellow, cream or bronze coloured pin-head sized blotches (known as stipples) occur between the leaf veins. These spots can join up to cover large areas of the leaf when ozone levels are high; 

2) Damage appears on the upper surface of the leaves, spreading to the underside in severe cases; 

3) Older leaves (towards the base of the stem and branches) tend to be more affected than younger leaves as damage is determined by the accumulated uptake of ozone over time.

Other causes of leaf damage: Powdery mildew 

on Ash leaves Fraxinus excelsior

Image: M.J. Sanz & V. Calatayud

"It’s also important to remember that there may be other possible causes of leaf damage, for example, fungal disease, viruses or insect damage. 

"Powdery mildew can produce white areas (hyphae of the fungus) on the underside of the leaf. 

"Leaf miners (larvae of insects that eat plant tissue) can cause linear patterns of necrotic tissue, while tiny pin-head sized red-spider mites may resemble ozone stippling but can be found crawling on both sides of the leaves and are not restricted to interveinal areas.

Other causes of leaf damage: Red Spider 

mites on French bean leaves 

Phaseolus vulgaris 

Image: E. Calvo

"The ozone smart-phone App will allow the creation of a database of records from many countries. 

"Ozone pollution is a worldwide problem and there are teams of researchers investigating the negative effects of ozone on crops, trees and semi-natural vegetation worldwide, for example, in the USA, Asia (Pakistan, China, Japan, India to name a few) and across Europe.

"Before using the App for the first time, we ask participants to register (with a username and password). 

Other causes of leaf damage: Leaf miner 

trails on Beech Fagus sylvatica leaf 

Image courtesy Innes et al., 2001

"App users can then upload photographs of ozone injured plants, while coordinates for the location where the injury was detected are recorded automatically using the phone’s GPS. 

"We also ask for some further information, including choosing the broad vegetation type of the damaged plant and the species name from a list (or adding this by hand), and describing the symptoms of ozone injury (including the colour, location on the leaf and age of damaged leaves).

App screenshot #1: click to enlarge

"Questions designed to assist with quality assurance, for example, specifying any previous experience of identifying ozone damage or plant diseases and describing recent weather and ozone conditions will also be asked. For guidance, the App contains an ‘Ozone information’ section, which includes details and photographs of the key symptoms of ozone injury.

App screenshot #2: click to enlarge

"It would be very useful if people could carry out regular monitoring for ozone damage throughout the summer at a site they visit regularly, for example, a garden, park or allotment. 

"If there is no visible ozone damage on the plant, the App also allows the user to record the absence of ozone symptoms.

"We are keen to gather information on both the occurrence and lack of ozone injury symptoms under different conditions. This will help us gain a more complete understanding of the extent of the ozone problem.

App screenshot #3: click to enlarge

"The App is available to download now. For those without a smart-phone, a web-based recording facility has also been created. Both the App and web recording form are available from our website.

"We plan to use the records submitted by App participants to add to the list of ozone-sensitive species worldwide and to validate risk maps, which predict where the risk of ozone damage to vegetation is likely to be the highest. 

"As ozone damage is more likely to occur in the UK during “ozone episodes,” we will send email alerts to registered App users to let you know the best times to go and look for damage. We would like to encourage people to get involved and download the App this summer, to help us to gather as much data as possible. 

"If you think you can help, please visit our website for more information".

For further details please contact:

Dr. Katrina Sharps

Centre for Ecology & Hydrology

Environment Centre Wales

Deiniol Road, Bangor

Gwynedd LL57 2UW

Tel.: +44 (0) 1248 374500

E-mail: katshar@ceh.ac.uk

Further reading

HAYES, F., MILLS, G., HARMENS, H. & NORRIS, D. (2007) Evidence of widespread ozone damage to vegetation in Europe (1990-2006). ICP Vegetation Programme Coordination Centre, CEH Bangor, UK. (http://icpvegetation.ceh.ac.uk/publications/documents/EvidenceReportFINALPRINTEDVERSIONlow-res.pdf)

SHARPS, K., HARMENS, H., HAYES, F., MILLS, G. & SCHAUB, M. (2014) Have you seen these ozone injury symptoms? ICP Vegetation Programme Coordination Centre, CEH Bangor, UK.  (http://icpvegetation.ceh.ac.uk/publications/documents/CEHOzoneInjury_webmidres.pdf)

New support group for beginner botanists

Great to hear from Notts. botanist Kevin Widdowson, Education Officer at Idle Valley Nature Reserve, about a new group he set up a few months ago to help support beginner botanists.

Kevin says "Botanical Keys and How to Use Them is a Facebook group set up to help beginners and improvers make sense of their field guides. 

"It was set up in response to hearing people comment about their initial apprehension and confusion with botanical keys. The aim of the group is to demystify the process and help people feel more confident with this valuable skill.

"We have a few regular items including a  'Term of the Day' feature and some set exercises on common plant species. We submit species reports to show how we have used a botanical key to reach an identification and we ask for advice when we get stuck. 

"There are discussions on equipment, resources, training and, of course, which field guides we prefer to use. (At the moment mine is The Vegetative Key by Poland and Clement).

"We currently have over 400 members and rising. Some of these members are very knowledgeable botanists who kindly share their experience with us beginners.

"It really does prove that a problem shared is a problem halved.

"Happy Botanising!"

Thanks to Kevin for letting us know about this new group and for giving beginner botanists a helping hand. Thanks also to the more experienced members in the group (including a few well-known BSBI botanists!) for giving up some of their free time to guide fellow botanists through the process of identifying a wildflower. When you're struggling with Stace or poring over Poland, it's great to have some botanical buddies for support! 

Botanical Keys and How to use Them is a closed group so Kevin says "To join, you need to find the group (either through this link or by using the Facebook search function ) and request membership. One of the administrators will then add you to the group."

Finally, here is one of Kevin's resources for helping people ID Malva sylvestris: