Monday, May 21, 2007
Here in Oxfordshire, spring has sprung and a hot, dry April followed by a wet May has bought my garden's California Poppies into bloom (see photo 1, click on it to enlarge) at (1.2,0.1) (see here).
You can see a close up of one of the rather beautiful flowers in photo 2.
Unusually for this site, I am in no doubt whatsover about the identify of this plant, since it was me that planted their parents, having grown them from seed some years ago. They seem to enjoy my garden's rather sandy soil and are systematically spreading their way through the borders.
With due apologies to my US readers I have to confess I was originally drawn to plant California poppy seeds simply because I thought the picture on the seed packet was attractive. I did not learn until very recently that my poppy is the Californian state flower. They were voted as such by the California State Floral Society on December 12th 1890.
The above fact, and virtually everything else I have learnt about the California poppy, I have garnered from the excellent site of Curtis Clark, who (his website informs me) has been studying Californian poppies for more than twenty-five years. It seems that Californian poppies are of interest to botanists since they are highly variable in the wild (in my garden both orange and white (photo 3) blooms appear) and a significant amount of taxonomics and genetics has been required to arrive at the currently accepted number of eight subspecies of California poppy. At one time over a hundred were listed.
Following Dr. Clark's key I arrive at the subspecies identification E. californica ssp. californica for my poppy, on the basis that in my garden the plant is an annual and possesses a 'receptacle rim' (I'm not entirely certain what this is but I'm guessing it might be the rim supporting the seed cases, some of which can be seen by enlarging photo 1).
The curious genus name Eschscholzia was given to the poppy by one Adelbert von Chamisso - a naturalist aboard a Russian expedition that visited California in 1816 - in honour of his friend one Johann Friedrich Eschscholtz who was the physician aboard their ship, the Rurik.
Finally, for no other reason than I always find it wondrous to think that something so tiny can contain within it all (or more strictly, about half) the information needed to create an entire new flowering plant, a photo (click to enlarge) of some California poppy pollen (40x magnification). The pollen grains themselves are the tiny spheres (for example, upper left) clinging to the orange anthers. Rather beautiful I hope you agree.
Saturday, May 19, 2007
Despite my previous posting on the sycamore having been 'live' for a full three hours, I have been amazed to receive not one comment from my legions of avid readers (hem,hem) pointing out the obvious evidence for the second life form in photo 2 of that posting. Photo 1 (left, click on it to enlarge) gives you a second close-up opportunity. Of course, on second viewing you will immediately kick yourselves for not having noted the orange leaf galls, obviously (!) evincing the presence of the microscopic mite, Aceria macrohynchus.
In truth, I myself didn't have a clue what the cause of my leaf's little orange pimples was, and I spent some time looking through literature on rusts and smuts (little fungal entities that also commonly attack leaves). Eventually however I came across the site written by the good people of Hainault Forest, and later, a site on the fauna of Cornwall in the U.K. and the RX Wildlife site, and from these arrived at the (presumed) identity of my mite. From the RX Wildlife site I also learn that my mite also goes under the pseudonyms Eriophyes macrorhycus and Aceria cephaloneus.
I have two rather basic questions about my mite that I have little hope of being able to answer myself on a reasonable timescale, and am therefore hoping someone out there may help with:
i) Have I got the identification correct (A. macrorhynchus), or are there perhaps other mite species that cause orange pimples on sycamore leaves?
ii) What purpose do the galls serve? Do they act as living quarters for my mite, or do they have another purpose?
Some 45,000 species of mite have apparently been named and it is believed that many more remain undiscovered. Given many are sub-millimetre I imagine it must be an enormous challenge, even for the experts, to know whether the mite you have under your lens represents a new discovery or simply one the 45,000 that people have seen before. I learnt recently that in the case of the related, but distinct, sub-class of arthropods, the spiders, the sure-fire route to identification is microscopic examination of the palps or epigyne. Are there similarly diagnostic features for mites or are other methods needed?
Finally, I would love to see a photo of my mite, but have entirely failed to find one on the 'web. I did however come across the excellent mite site of the US Dept. of Agriculture. I did not find a picture of A. macrorynchus, but did find not only a photo but amazingly also a video of the Canadian Thistle Rust Mite Aceria anthocoptes. Since I understand that the images from the US DA are in the public domain, I'm reproducing it here (unless someone can tell me I shouldn't?). Since the Thistle mite above and my sycamore mite are in the same genus (Aceria) I'd like to believe they're of similar appearance. I'd be delighted if someone can point me to a photo of macrorynchus however.
Saplings of Sycamore trees (Acer pseudoplatanus) (see photo 1 - click to enlarge) spring up regularly in my garden. Examples can currently be found at (0.9,1.3), (1.8,2.0) - see here - and at a few other locations in my garden. I confess to hacking back these invasive and fast growing visitors. They are remarkably resilient plants however, and will come back time and again even when chopped right back to ground level. Apparantly the hardiness of sycamores, which includes a tolerance for salt, makes them a useful option for planting in situations where few other trees will grow - for example on the salt-sprayed verges of motorways ('highways' to those of you visiting from the States).
Sycamores are members of the maple family. A fact that, once known and considering the shape of the leaves, seems obvious, though I confess initially came as a surprise to me as I automatically associate maples with maple syrup, an exotic foreign substance to a born-and-bred Englishman such as myself!
The leaves of maples and sycamores are so distinctive that you are unlikely ever to struggle to identify one, but (as I learn from my copy of the Collins Tree Guide by Johson and More) if ever you are in doubt it is useful to know that relatively few types of tree have opposite leaves (leaves that sprout symmetrically from a point on the stem - see those in the centre of photo 1), and of those that do (ash, eucalyptus etc.) none can be confused with maples.
Though widespread and common, sycamores are not indigenous to Britain, their origin being high ground in Southern Europe. It seems they arrived some time between the Roman occupation and the 16th century.
Although it does not strictly relate to my garden, from the above book I also learn that there are a number of sycamore clones, including a lovely variegated variety that goes by the delightful name Simon-Louis Freres and which, by happy chance, I came upon on a walk recently, hidden away off a quiet country lane near the Oxfordshire village of Cuddesdon.
From a search of the Internet I learn that the word sycamore derives from a confusion that sycamores bear some relation to the fig tree Ficus sycomorus (they don't). Also that the Latin pseudoplatanus, literally false plane is a reference to the 'Platanus' genus of (eleven species of) trees which, although it contains the so-called Arizona Sycamore, is distinct from the acer genus that contains my sycamore. The sycamore is sometimes alternatively called the Scots Plane. Finally, that acer is from the Latin sharp. Here I find some disagreement between sites with some claiming this is a reference to the sharply pointed leaf of the sycamore (see photo 2), and others that it is a reference to the fact that sycamore wood makes good (i.e. sharp) spears! I don't know which is correct but find the latter much more appealing and was delighted to come across this article from the annals of British Archaeology which tells you how to make your very own sycamore spear, in imitatation of the 400,000 year old 'Clacton' spear (though this was in yew - though of course (!), you knew that already).
Finally I am sure you are all desperate to know what is going to happen to the sycamore in photo 1. Well, firstly I am going to let it grow a little while longer. Then, when I find a quiet moment, I am going to turn it into Oxfordshire's very own Clacton spear, hopefully to be re-discovered by an archaeologist 400,000 years from now!
Saturday, May 12, 2007
Photo's 1 and 2 (click to enlarge) show a weed that grows beneath the hedge at the rear of my garden (specifically, at (0.8,2.0) - see here). Turning to my copy of The Wild Flower Key (Francis Rose, publ. Penguin Books) I'm confident my weed is Herb Robert (Geranium robertianum).
Herb Robert is part of the Crane's Bill Geraniums, so-called as apparently the seed cases have that shape. I don't have a photo of this but will try to post one later in the season when the seed cases are well developed.
Left undisturbed Herb Robert has no particular smell, but bruise the leaves and a pungent odour emerges that, to my nose at least, is a cross between ginger and cat pee! Despite this off-putting feature, it seems some are happy to use Herb Robert as a herbal 'tonic' and it gets a mention in the famous writings of the 17th century English herbalist Nicholas Culpeper:
"Herb robert is commended....to stay-the-blood; it speedily heals all green wounds, and is effectual in old ulcers in the privy part"
Not advice I can endorse!
An obvious and intriguing question is who was Robert? Here, I have to say my web searches have drawn blank. According to this site possible candidates are a French monk Robert of Molesme (d.1110); Robert Duke of Normandy (d.1134) or a Bavarian St. Rupert of Salzberg (d.718). Whether these are the only candidates and which has the honour of being the one, true 'Bob I haven't been able to determine. If you're reading this and know, please leave a comment.
Richard Tofts has put a scholarly review of Herb Robert's biology online, from which I learn that the British Isles can be divided up into about 3,500 10x10km squares, and that you'll find Herb Robert in just about all of them. This prodigious ability to spread and colonise has led to G. robertianum becoming a serious problem-weed in woodland in the USA, where it is an introduced species.
For a fascinating photo of a Herb Flower taken in ultra-violet light (a region of the spectrum into which which many insects can see) see here. If you'll permit me a moment of hubris however, I have to say one of the prettiest photo's of Herb Robert I've seen is the one that emerged when I put a flower under my microscope at 40x magnification (photo 3) and saw the dozens of tiny yellow pollen balls clustering the flower's reddish-purple anthers (the presence of red or orange anthers identifies my plant as G. robertianum incidentally, rather than the similar-looking, though somewhat smaller, Little Robin (G. purpureum) which has yellow anthers).
Though to many gardeners it is a weed I shall leave my Herb Robert growing under my hedge. You never know when the ability to prepare a poultice that smells like cat pee is going to come in handy!
Beneath a large stone (at (1.7,1.7) -see here) I found the beetle shown in photo 1 (click to enlarge). Sadly, in moving the stone I must have inadvertently squashed him or her (can anyone tell me how to sex my beetle?) because shortly afterwards he (or she) dropped dead. I was, and am, genuinely sorry about this as I try hard never to harm the creatures appearing in this blog. It at least gave me an opportunity to examine my beetle in detail.
Photo 1 does not fully capture the colour of my beetle. In direct sunlight it was a more vivid metallic blue. Photo 2, a 40x magnified view of part of my beetle's back, shows up the colour more clearly.
Beetles (unlike earwigs! - see here) comprise the insect order Coleoptera. They are in part distinguished from other insects by the presence of :
i) hard or leathery elytra (wing cases) in place of forewings, and
ii) biting (rather than sucking) mouth parts.
The problem for any amateur attempting to identify a beetle's species is that there are just sooooo many of the little fellows. The oft-repeated quote is that of British geneticist, J. B. S. Haldane (1892-1964), who, when asked what he could infer about the mind of God replied that he must have "an inordinate fondness for beetles". Apparently, the book to own (I don't) as a serious beetle lover is the Die Kafer Mitteleuropus (The Beetles of Central Europe) which, as of 1981, ran to ten volumes. According to my (single volume) Beetles (K.W. Harde, Octopus Books 1984) some 370,000 species of beetle are known to science and perhaps five million (!) await discovery. In Europe there are 8,000 species and in the U.K. alone 4,000. What this all means in practice for the amateur is that it's best to cultivate a sense of satisfaction in being able to pin a beetle down to one of the 100-or-so (British) families. Any progress in identification beyond that is a bonus.
So, how does one set about identifying a beetle's family? As is so often the case in natural history, the key to successful identification is the careful recording of all the little features that one overlooks at first glance: do the elytra entirely cover the beetle's abdomen or stop half-way down; are the rear legs longer or shorter than the front; are the antennae 'plain' or 'feathery', how many segments do they have; do they taper to a point or end in a club-like swelling? And so on. In my case I was greatly assisted by the A Key to the Families of British Beetles (D.M. Unwin, no. 166 of Field Studies Council publications). This key is excellent for the amateur as it puts an illustration beside every piece of technical jargon - a wonderfully simply idea, but it is amazing how many books don't do this and how difficult they can be to use as a consequence.
Following Dr. Unwin's key I'm fairly confident my beetle is a member of the family Carabidae. A particular feature of this family is the presence of large stubby trocanters ("lumps" on the hind leg femurs) photo 3 (40x magnification) it's clear that my beetle has exactly this feature. Turning back to the book by Harde mentioned above, a picture therein of the particular Carabidae species Pterostichus cupreus seems a possible candidate, but without a more detailed description than is given, I don't claim a high level of confidence in this identification. If you're reading this and have a better suggestion do please leave a comment. If my beetle is P. cupreus apparently he/she is predatory (as are most members of Carabidae), feeding on aphids.
Finally, let us pause for a moment's silence in memory of my dear, departed beetle. Gone, but not...er...identified.
A huge thankyou goes to Oleg who, in his comment attached to this posting, identifies my beetle as the carabidae beetle Leistus rufomarginatus. This site has a good close-up photo. Thanks again Oleg.
Monday, May 7, 2007
I have a galvanised-metal incinerator bin in my garden, the lid of which can see be seen in photo 1 (I am sure you will be fascinated to see it!). Said lid has, for some months, been lying untouched at one edge of my lawn (at (1.2,1.9) - see here). On a whim I lifted it recently expecting I might discover a beetle or two to act as raw material for this blog. I was surprised and delighted however, to discover the entity shown in photo 2 (click on it to enlarge).
I feel fairly confident in identifying my mushroom as the Yellow Morel (Morchella esculenta - see Rogers mushrooms for more photos), an edible mushroom highly prized by chefs (though it is worth adding that morels should not be eaten raw and worse, the superficially similar-looking False morel (Gyromitra esculenta) can be deadly poisonous).
It is probably no coincidence to find a morel in close proximity to my garden incinerator since morels are often associated with burnt ground. According to my copy of Fungi (B. Spooner & P. Roberts, publ. Collins New Naturalist and refs. therein) in times past "the peasants...of germany...set fire to forests in order to obtain these fungi".
Why the curious shape? The short answer is that if, like fungi, you are in the business of reproducing by allowing air currents to carry away your spores, it pays to maximise the surface area you present to the passing breeze; Hence the many pits and grooves on the morel.
A more in-depth answer (of sorts) is as follows: The fungi are a huge kingdom of perhaps nine-million (!) species outnumbering vascular plants by perhaps six-to-one. People who study fungi (mycologists) break this kingdom down into two great divisions ('phyla'), the basidiomycota and the ascomycota. The majority of the more familiar mushrooms and toadstools (i.e. "caps-on-stalks with gills underneath"), including most edible mushrooms, fall in the basidiomycota. The ascomycota on the other hand are generally less familiar, although both morels and truffles fall in this phylum. Unlike the basidiomycota with their "gills", the ascomycota typically try to maximise their surface area by presenting concave "cups" to the air. The morel's complex surface is nature's attempt to pack lots of 'cups' side-by-side.
Under the microscope there is a more fundamental difference between basidio- and ascomycota: Whilst the basidiomycota produce 'free' spores on the spaghetti-like hyphae (see a previous posting) that make up the fungus (like apples on the branches of a tree), the ascomycota on the other hand produce spores inside special hollow tubes called 'asci' (like peas in a pod). The asci eventually rupture to liberate the spore. I gathered a small piece of my morel and at x1000 magnification (1 small graticule division = 1um, see photo 3, click to enlarge) the asci are clearly visible. One touches the numbers '0' and '1' on the graticule. A free spore is also visible at '6' .
Finally, I learn from the book above that the world market for morels is worth more than one-billion pounds per annum. "Lot 1 ladies and gentlemen, a genuine Oxfordshire yellow morel. Shall we start the bidding at one-hundred guineas...?"
As you will see from the comments, those familar with fungi are appreciative of my good fortune in finding a morel. I cannot resist adding a quote therefore, that was sent to me by an acquaintance. I am informed it is taken from It's My Delight by Brian Vesey-FitzGerald published in 1947 "Hares....are also very fond of fungi, especially the mushrooms, the various puff-balls, Scotch-Bonnets, Shaggy Ink Caps, and several others. They will invade gardens to get at morels which often grow in borders" [my emphasis]. Rather sad to think of what has been lost.
Thursday, May 3, 2007
Photo 1 (click on it to enlarge) shows a dandelion I found growing in my garden (at (0.6,0.9) -see here). In an attempt to learn something about dandelions I have been reading the Dandelions of Great Britain and Ireland (A.A. Dudman and A.J. Richards, BSBI Handbook, 1997).
Dudman and Richards' book is a tour-de-force of field botany. According to the authors, no fewer than 235 "species" of dandelion have been recorded in the British Isles. They give painstaking botanical descriptions and illustrative plant-silhouettes of them all and distribution-maps for most.
Why the quotes around species in the last paragraph? Because dandelions are not like most other plants; Dandelions reproduce apomitically (asexually). This means that all the seedlings from a parent plants are identical clones. The authors describe how planting out the seeds from a dandelion in a row will, under identical growing conditions - for example in a tomato "grow bag" - result in a row of identical baby plants, an idea that for some reason appeals to me greatly and is something I'm determined to try at some point.
Although individual dandelions asexually produce clones, over time mutations emerge in the population: hence the 235 dandelion types listed in the book.
So, how do you begin to tell different dandelion strains apart? The answer is by painstaking examination of the features of a given plant: Are the leaves uniformly green, or are they blotched in places?; What colour is the petiole ? (the mid-vein in the leaf) (example colours include green and purplish-red); Is the scape (the flower stalk) smooth or minutely hairy?; What shape are the bracts (the small "leaves" surrounding the flower-head like a collar) ?; What colour are the stripes on the back (see photo 2) of the ligules (the flower 'petals')?; What shape are the leaves?... There are a dozen features to take into account...
Or at least that's the theory!! When it comes to separating dandelions, as the authors themselves admit: "confusion and frustration [lie] ahead: dandelions are difficult!"
The problem is that dandelion features are enormously variable ("plastic"). Take two clones, grow them under different conditions of light, humidity etc. and entirely different plant shapes and features can emerge. The authors recommend that the only really practical way to build up experience of identifying dandelions is to build up a large collection of dried specimens.
Where does this leave the amateur? Frankly, mired in uncertainty! In the case of my dandelion I can confidently say it was not found on a Scottish mountain top, nor are the capitulas (the flower heads) less than 3cm in diameter. Following the key of Dudman and Richards this means my dandelion in a likely member of the "genus" Ruderalia. I struggle however to bring my dandelion down to a specific one of the 120+ Ruderalia "species"; I can find no evidence of pollen on my dandelion, which would make it most likely to be Taraxacum subhuelphersianum - except that the leaves of this plant are described as "distinctly pale, slightly greyish", which mine aren't. I leave you to judge for yourselves.
Two things intrigue me about dandelions:
One - Most plants flower to attract insects for the purpose of cross-pollination ("sex"). As above however, dandelions don't "do sex". Is the capitula (=flower head) a redundant evolutionary relic in dandelions therefore, or does it serve some other purpose?
Two - For the amatuer, a microscope proves enormously handy when it come to identifying moss and fungi. Photos 3 and 4 show my attempt at a microscopal photo of a dandelion seed (achene) and pappus (=the 'feathery' bit on the seed ). Both show a wide array of bumps, hooks and other features. I would love to think that these features are diagnostic and someone out there is busy putting together a key to dandelions based around their features visible under a low power microscope. Very possibly there is nothing in this suggestion. On the other hand, if you're that person do please leave a comment.