Natives (British)

That Plant’s Odd

Any idea what teratology is? I’ll tell you: “the study of abnormalities of physiological development”. And for almost twenty years Martin Barber, from Wiltshire in the west of England, has been producing a newsletter devoted to abnormalities in plants. It’s called That Plant’s Odd. Says it all, really.

The newsletter deals with unusual forms of mainly wild plants and, as the introduction to the very first edition in 1993 says: “The scope of the newsletter is to include any material concerning native plant aberrations.” That is: odd plants. Variegations of various kinds feature often, as well as yellow- and purple-leaved forms, and there are plants with flowers in unusual forms or in unexpected colours; as well as plants with contorted branches or with strangely formed flower spikes. Anything that is, frankly, just a bit odd. The yellow-leaved form of the British native stinking hellebore, Helleborus foetidus ‘Chedglow’ (above, click to enlarge) is one of Martin’s finds.

That very first issue of That Plant’s Odd includes records of a white annual corn poppy with red blotches at the base of the petals (sounds gorgeous), of wild elders with pink flowers and another with purple stems, while issue two discusses two variegated wild roses, variegated dandelions, and forms of the classic British native bluebell with leafy growth amongst the flowers.

I’ve found a few plants that qualify, over the years, including two or three very attractive lawn daisies with yellow leaf veins one of which was in a lawn at the National Botanic Gardens in Dublin. Last spring, at the MercuralisPerennisPlusGoldBarnack Hills and Holes Nature Reserve, I came across just one plant of the common British woodland flower, Dog’s Mercury’ (Mercuralis perennis) which was almost completely yellow (left, click to enlarge).

It’s also worth remembering that many of today’s most dramatic varieties of Heuchera are derived from unusual forms collected from the wilds of the American forests.

As well as publishing That Plant’s Odd, which I have to say is more appreciated for its content than for its elegant design, Martin also runs a small nursery specialising in these unusual plants called Natural Selection and is the author of Appreciating Lawn Weeds and of Botanical Monstrosities: A First Step in Plant Teratology though both these are hard to find.

A two year subscription to That Plant’s Odd (six issues) by costs just £7.00 for British subscribers. Send a cheque to: That Plant’s Odd, 1 Station Cottages, Hallavington, Chippenham, Wilshire, SN14 6ET. Martin hopes to be able to deal with international subscriptions soon.

Book Bullet: Weeds by Richard Mabey

Weeds by Richard Mabey - Book ReviewBritain’s most distinguished writer on natural history brings his accessible erudition to bear on plants which can both destroy precious ecosystems and beautify urban dereliction and war torn landscapes.

Considering both how eucalyptus took over the Florida Everglades to such an extent that in some areas there were 8 million trees per square mile and how native poppies sprang up so memorably on European battlefields, this effortlessly wide ranging and engagingly written book.

"Weeds, as a type, are mobile, prolific, genetically diverse,” says Richard Mabey. “They are unfussy about where they live, adapt quickly to environmental stress, use multiple strategies for getting their own way. It's curious that it took so long for us to realize that the species they most resemble is us."

Weeds: In Defense of Nature’s Most Unloved Plants by Richard Mabey was published recently in North America by Ecco and last year in Britain by Profile Books.

  • Combines scientific research, folklore, personal experience, fun and fine judgment in one enjoyable book.
  • A vital read for gardeners, naturalists, and anyone interested in both native plants and invasives.


Invasives in Britain: a balanced view

Himalayan balsam: 'largely only displaces other aliens or thuggish natives,' says David Pearman. Image used under the Creative Commons Attribution-Share Alike 3.0 Unported license.There’s a lot of nonsense talked about invasives so it’s refreshing to see one of Britain’s most respected botanists talking some real sense. David Pearman is a former President of the Botanical Society of the British Isles and a leading light in the development and publication of one of the most vital British plant publications of our times, the New Atlas of the British and Irish Flora.

In a piece entitled The Alien Invasion Myth which appears in the current issue of The Garden, the membership magazine of the Royal Horticultural Society, he writes: “For the last 20 years I have coordinated our Society’s largest network of botanical recorders (from the Botanical Society of the British Isles): together we have accumulated about 18 million records, covering the entire area and 4,000 species. In simple terms, the data shows that most aliens are rare; that they occur overwhelmingly in and around towns and transport networks; and they are generally uncommon in the semi-natural habitats that we most want to preserve. Recording alien plants is, broadly, a recent phenomenon, and all extrapolations are to be taken with a pinch of salt.”

He goes on: “But the real, inescapable line is that our countryside and flora is changing like never before, mainly from abandonment of traditional management practices and pollution. It is largely ‘native’ plants that are to blame – look at the chalk downlands of southern England (choked with gorse on the dip slopes) or our rivers (a vast increase in reeds, due to higher nutrients).” 'Native Bluebells, Hyacinthoides non-scripta, are under only a minute and local threat from garden outcasts,' says David Pearman. Image © (all rights reserved)

Of course the situation is slightly different in North America where there’s more genuinely natural habitat; in Britain almost all habitats are, as he puts it, “semi-natural” – most woodlands, meadows, mountains and aquatic habitats show the hand of man in some form. But in North America there’s also a tendency to rip out any non-native plant that turns up before anyone has had the chance to record its distribution or study its tendency to spread – or, perhaps, its tendency simply to fade away.

Changes in management, and pollution, are the drivers of change in Britain’s natural habitats, says David Pearman. We can hardly blame plants for what happens as a result.


Himalayan balsam image by ArtMechanic used under the Creative Commons Attribution-Share Alike 3.0 Unported license. Thank you.

Ivy reveals how nature is nuanced

Ivy growing on a stone wall. Image © (all rights reserved)In North America, in spite of uncertainty about exactly which species is involved, ivy is widely condemned as an invasive plant that smothers natural vegetation. And it’s true, whether it’s Hedera helix or H. hibernica that’s causing the problem, ivy can be a menace in some areas although in much of the country it doesn’t grow at all and in other areas it remains well behaved.

But seeing this ivy on the wall of an English stone cottage (left, click to enlarge) reminded me that ivy can cause other problems even in Britain where it’s a valuable native plant popular with insects and birds and a widely popular ornamental climber for walls.

It has clearly once covered this limestone wall but has been cut off at the root and most of the growth removed. But it’s still growing, rooting into the mortar and renewing its hold. Looks like a job for Round Up, now, because the mortar traditionally used between the stones is relatively soft; when it’s pulled off, the mortar tends to come away too. Click he picture to enlarge it and you can see.

On modern walls built of hard bricks and hard mortar, a completely opposite problem can arise. In the picture below (click to enlarge), the bricks and mortar are so hard that the short aerial roots with which ivy stems grip their support have failed to take hold well. The weight of a rainstorm has pulled the ivy right off the wall.

These situations serve to remind us, on both sides of the Atlantic, that enthusiasm for a plant, and condemnation of it, are not simple black-and-white issues. Nature is nuanced, rarely is a simplistic view justified.
Ivy falling off a brick wall. Image © (all rights reserved)

Mapping plants

MonotropaMapUK900 When you’re trying to identify local wild flowers, or see if a plant is invasive in your area, plant distribution maps for individual species are invaluable. Plant distribution maps simply show you where in the country individual species grow. Britain and Ireland’s online plant map website, the Online Atlas of the British and Irish Flora, is superb.

This is the online version of the truly stupendous – but enormously heavy and expensive – book The New Atlas of the British and Irish Flora. On the site, you simply input the common or botanical name of the plant, and the next page brings you a fairly basic map together with a text summary.

However, click on the Maps button and then on Link to Interactive Map and you come to a topographical map with the distribution of the plant clearly marked. You can zoom in and out, and there are other interactive features. The country is divided into 10Km squares and the map shows the squares in which the chosen plant grows. This  is the distribution of Pinesap, Monotropa hypopitys, that I wrote about here recently, in Britain and Ireland (above, click to enlarge).

The site allows you to zoom, overlay county boundaries, get information on the records in individual squares. I’ve zoomed in to illustrate mostly just England - which is about the same area as our state here in Pennsylvania. Produced by the Botanical Society of the British Isles and the Biological Records Centre I have to say, this is absolutely brilliant.

In the United States, the Department of Agriculture’s Plant Database is the place to start. Again, search on the common or botanical name and a distribution map for the whole country comes up on the next page with a note on whether the plant is native or introduced. Click on your state and you get a county-by-county distribution map. Below (click to enlarge) you’ll see the county-by-county distribution for Pinesap in Pennsylvania.

In North America, individual states have their own flora mapping projects. Here in Pennsylvania, the Pennsylvania Flora Project eventually brings you the same map as the USDA site. The Calflora site is a much more impressive resource for California, again with sites shown on topographical maps.

Knowing whether a plant has ever actually ever been found in your area can be a big help when trying to identify wild flowers, especially when trying to distinguish between similar species.


Pinesap – an intriguing American and British native

Pinesap, Monotropa hypopitys, Monotropa hypopithys. Image ©
Pottering about in the woods, looking at the downed trees from the hurricane, I came across this little clump of Pinsesap, Monotropa hypopitys. It’s not a rare plant, but I’d never spotted it near the house before. The name, Pinsesap, is said to be derived from the fact that it grows under pine trees and saps its juices. It grows in Britain, too, where its common name is, rather mysteriously, Yellow Bird’s-nest.

Like the entirely white Indian pipe, Monotropa uniflora, which we have in the garden as well as the woods, Pinesap has no chlorophyll and was always thought to be a saprophyte – getting its nutrients from rotting leaf litter. It was also usually placed in its own family, Monotropaceae.

But the world of the pinesap has been turned upside down! Well, no, the pinesap carries on as it has for thousands of years. It's our understanding of pinesap that has changed dramatically.

First of all, it turns out that rather than using rotting woodland leaf litter for its nutrients, it’s actually parasitic on a group of woodland fungi. Also, the latest thinking is that it belongs, rather surprisingly, in the Erica family with rhododendrons and heathers. Finally, there are some who believe that it needs separating from the Indian Pipe, Monotropa uniflora, into a genus of its own. The genus Hypopitys has been created for it – and in that case what would its new name be? Instead of Monotropa hypopitys it would then be called - Hypopitys monotropa! Oh, those botanists like a joke...

Oh, and there’s another odd thing about the North American form of this plant. It comes in a yellow version that flowers in summer, and also the reddish version seen in the picture (above, click to enlarge) that flowers in the fall.

Anyway, it’s good to have such an intriguing plant turn up in our local woods.

Helleborine orchids in our garden

While I've been woozing over my jet lag, judy has been inspecting the increasingly prolific orchids in our Pennsylavina garden.

Epipactis helleborine, Broad-leaved Helleborine Orchid. © (all rights reserved)
It’s that time of year at the lake when the hardy Epipactis helleborine orchid is in bloom again. It’s not a native orchid – only one Epipactis, E. gigantea, is a native American. The Broad-leaved Helleborine Orchid is from Europe originally, and, in fact, in some places in the United States (especially Wisconsin) this beautiful plant is invasive, so much so that it’s called the Weed Orchid. It’s been naturalized in the States since at least 1879. (I read that originally it was introduced by American colonists as a medicinal plant, theoretically good for gout. There are scientific studies showing its in vitro activity as an antiviral against HIV-1 and HIV-2 as well as influenza A.)

Here in our 1400ft (425m) high Pennsylvania mountain garden, though, the helleborine orchids just kind of pop up, usually one at a time in scattered spots, often gone the next year, and we are rather fond of the gently random nature. Although they spread by rhizomes, ours seem to spread more by seed, so clearly we have conditions conducive for the necessary mycorrhizal fungi that help the seeds germinate. Generally these orchids grow in semi-shade, but sometimes in lots of sun, and though supposedly Epipactis prefer moist – or even wet – environments, ours are exceedingly adaptable and drought-tolerant, a good plant for dry shade.

Broad-leaved Helleborine Orchid, Epipactis helleborine,daylily,fern. ©GardenPhotos.comHelleborines make tall spikes of little half-inch to three-quarter inch (1.2-2cm) flowers; some of our plants have nearly 50 blooms, with the inflorescence reaching over 2ft (60cm) high. This year there seems to be a vast number of pollinators on the ones in the most shade (I’ve noticed bees on them), and the flowers, which open successively from the bottom up, are turning into seedpods almost immediately upon opening.

Last year I took some seedpods and scattered them around the various garden beds, so there are some unexpectedly nice woodland plant combinations this month. With green sepals and lavender-tinted petals, the helleborine flowers are looking lovely with a lavender-toned Japanese painted fern cultivar (Athyrium nipponicum var. pictum) that we’ve lost the tag of, amid the lacy sweet woodruff (Galium odoratum). A few are blooming under the Hydrangea arborescens ‘White Dome’, which is also in full flower, and one helleborine has struck up the tallest presence our main garden border in a fair amount of sun; it’s opening much later than the others.

The name “helleborine” supposedly is because they resemble hellebores. I don’t get it. No part of them, not the flowers, and definitely not the plant habit, look like hellebores in the least to me. I’ve even got the two growing side-by-side. Linnaeus must have been a little drunk on Swedish schnapps when he named the species.

Native plants are not always best for native insects

Wildlife of a garden,Jennifer Owen. Image ©RHS Native plants are not always best for native insects, non-natives also have an important role. That’s the message following a thirty year study in a British garden. For thirty years award-winning ecologist Dr Jennifer Owen studied, identified – and counted! – the insects and other creatures that visited her suburban garden in the English Midlands. And detailed it all in her invaluable book Wildlife of A Garden (Available in North America, and available in Britain) published by the Royal Horticultural Society.

She grew well over 400 different plant species - garden plants and weeds, natives and non-natives - in her garden (below, click to enlarge) which measures just 741square meters (8000 square feet). And she counted 23 species of butterflies, 375 species of moths, 94 species of hoverflies, 121 species of bees and wasps, 305 species of bugs, sawflies, lacewings and related creatures; 21 species of beetles, 122 species of other insects including two ants – all in her suburban garden. And 138 other invertebrates. And 57 birds and six mammals. Wildlife of a garden,Jennifer Owen,garden,Leicester. Image ©RHS

And as well as counting with extraordinary determination and great skill at identifying this vast variety of creatures – she also studied their food plants. And what did she find?

Dr Owens found that non-native species were better as food plants for moth larvae than native species. Moth larvae used 27% of the native species in the garden as food plants, and 35% of the alien plants. And 46 species of moth fed on 40 native plants in the garden, while 75 alien plants provided food for 38 species of moth.

She also looked at the four moth species with the most varied diets and the plants they ate. One ate 78% non-native plants, one ate 83% non-native plants, one 62% and one 79% non-native plants. They definitely didn’t favor natives. Of course, we don’t know how much of each plant each moth actually ate – after all, Dr Owen needs to get a few hours sleep each night.

And finally, what were the most popular food plants for moths? Plants in the rose family come out top, with seven native species and five non-native species used by 27 species of moth. And one of those native species, Potentilla fruticosa, is so rare in Britain it might almost be non-native. Next comes the Buddleja family represented only by the Chinese Buddleja davidii and used by 19 species of moth. The daisy family, the largest family of garden plants, hosts just 13 moth species all of which feed on aliens and only two of which feed on natives. And just to be clear: these are all British native moth species.

Wildlife of a garden,Jennifer Owen,tortoiseshell,aster. Image ©RHS You get the picture. I could go on, but this is just a blog post of a few hundred words. Read the book. OK then, one more thing. Dr Owen reports that of the 15 most widely used food plants in the garden nine are non-natives and only six are native. And some people think that introduced plants have no native larvae feeding on them at all!

This really throws the “natives are best” notion out of the window. We may like to think that natives are best, but they’re just not. And can’t we trust the insects know what they like to eat – wherever the plants come from? So why don’t we plant what the larvae actually like to eat, instead of what we think they ought to like?

This is an extraordinary piece of research summarized in a very readable and well illustrated book.

In my next post here, I’ll be looking at which buddlejas are best for adult butterflies. Because now we know.



* This post was originally headlined: "Alien plants are better for insects than natives – it’s official!" But after reflecting on the comments below, I modified it and substituted a less sensationalist headline. I also modified the introduction.

* At present, for some reason, and don't seem to realize they have the books in their own warehouses and are not listing them as being available. They are available for shipping anywhere in the world from The Royal Horticultural Society.

Primroses I won't have in the garden

Primrose,Primula,horrid,color,colour. Image © (all rights reserved)
Strolling through the centre of town back in Northamptonshire today, I couldn’t help noticing the most horrible primroses offered for sale at the florist (above, click to enlarge). They were gross travesties of our delightful native wild primroses - in more or less the same shade, but in this hybrid the flowers are about three or four times the size of a wild primrose.

In fact one of the plants had a strange, rather putrid, green caste to its flower colour; in both the foliage was completely smothered by the far-larger-than-life flowers making them look noticeably unnatural; and they were offered as a mismatched pair in a lurid pink painted steel container – for £9.50 ($15.30). No thank you.

Primrose,Primula,vulgaris,wild,native. Image © (all rights reserved)
Then a few minutes later, in pot in a front garden, I spotted a true wild primrose, Primula vulgaris, plant looking delightful in a (slightly battered) blue-glazed pot (above, click to enlarge). I know which I’d rather have. And even in those pink pots, wild primroses would have looked good

The lesson? Bigger is not necessarily better.

Hellebores at the airport

Helleborus,foetidus,stinking,hellebore,Stansted. Image © (all rights reserved)It’s not often you find hellebores growing by the side of the road in Britain, least of all by the entrance to one of London’s major airports. But on the way to lecture in Essex on Sunday, I rounded a corner by London’s Stansted Airport and came upon this drift of British native stinking hellebores, Helleborus foetidus, growing right by the side of the road (click to enlarge).

Quick look in the mirror, screech to a stop, take a quick snap through the passenger side the window and on the way without disrupting traffic or getting hit by a truck. The point-and-shoot is always ready, just in case.

The plants are growing amongst the British native dogwood, Cornus officinalis, with its dark red stems and really light up this shady bank. Even though the flowers are not yet open – it’s the pale leafy bracts that are so bright.