Crab Apples and Jeelie Bags
Scotland’s native wild apple tree (Malus sylvestris) is an attractive, solitary and often unassuming tree with a big history. It is a key player in the domestication of the apple, with Malus domestica, and all its many cultivars, boasting M.sylvestris as one of its progenitors. Its tart fruits are well known to small mammals, cattle and aficionados of fine Scottish preserves. Tradition dictates in my family that come crab apple season the (questionably ancient) jeelie bags, handed down to my mother from hers, are brought out and sacks of tiny apples are scrounged, boiled and smooshed as the acidic sweet aroma fills the air and the liquid slowly drips through the bag to form a jewel like preserve.

Folklore, DNA and Pabaigh Mor
The apple has a rich tapestry of folklore associated with it: It is of course the Forbidden Fruit to Adam and Eve, dooming humanity to a life in the knowledge of good and evil. To the Celts it was a sign of fertility and a symbol of long-lasting love, owing to its ability to be stored long past picking. In the Irish folk tale ‘Connla the Fair’ a young prince is committed to a winterless existence in the Fae after eating an apple given to him by a faerie woman he falls in love with. It is said that by throwing an apple pip in the fire while saying your lover’s name you can determine whether they are faithful or not depending on the pip’s propensity to explode. In Norse mythology Idun, the goddess of spring and rejuvenation, keeps the golden apples of immortality which the gods must eat to maintain their everlasting life. There are golden apples, too, in Greek mythology that held the golden light of sunset, gifted to Hera and protected by the three Hesperides (nymphs of the apple tree; or, Epimeliads) and assisted by a hundred headed dragon named Ladon. And, in a multitude of other Celtic tales, it is the key to the gateway into the otherworld, and thus, mystery.

With scientific advances in DNA analysis coming to the forefront, as well as plant breeding programs producing a plenitude of larger, more delicious, more disease resistant fruits for our consumption, it is easy to see how some of the magic, myth and wildness of the apple has fallen out of fashion. But there is still magic about… a lone Malus sylvestris found in 2003 on an inaccessible cliff edge on Pabaigh Mor, an island off the west coast of Lewis, is still shrouded in a healthy chunk of mystery. How long has it been there? How did it get there? No one can be quite sure – the lone remains of an orchard from generations before perhaps? Or did a single seed hitch a ride along with a human? Is it the same tree having lasted generations or is it a repeating site of progeny? Is it self-pollinating or does it have a secret lover (or, for the avoidance of getting too carried away, a genetically compatible partner to pollinate it) nestled in a cliff somewhere else on the island? While looking at the DNA can tell us huge amounts in exquisite detail – confirming for instance that it is, in fact, a pure Malus sylvestris – some of the other mysteries surrounding the tree still require a significant amount of field work, exploration and ample imagination.

Hybrids and Morphology
My trip into the world of apples came somewhat accidentally: having a deep, but rather directionless, fascination with the hybridisation of wild species populations, I started assisting with field work on a project at RBGE studying the morphological differences between Malus domestica, M. sylvestris, their F1 hybrids and subsequent backcrosses. My interest quickly secured itself to a focus.

There is no denying how incredibly important DNA analysis is in accurately identifying species, but there is something pure and, yes, magical about the idea of being able to tell species apart by their morphology alone. Sometimes, however, this proves to be very difficult as hybridisation brings with it an amalgamation of varying characteristics. The fantastic thing, though,  is that it needn’t be either or. Looking at both DNA and morphology together we have an even greater tool in trying to unearth the often minute and seemingly inconsequential differences between hybrids and their parents. In the case of domestic and wild apples, for instance, it is possible to determine with a relative level of conviction whether you are dealing with either Malus sylvestris or Malus domestica. In an extremely simplified assessment: M. sylvestris will most times have no hairs on the lower leaf surface and the fruits will generally be smaller than 30mm in diameter while in M. domestica the underside of the leaf will often have a felted covering of hairs and have fruits often closer to 60mm or larger. When it comes to hybrids however, there is, seemingly, far less rhyme or reason, with each individual plant’s morphology consisting of different and varied characteristics from its parents: an F1 leaf could be hairy, slightly hairy or not hairy at all, for example.

Exploring Landscapes and Navigating
Collecting these morphological data has led me to some stunning areas of Scotland and some equally stunning trees, transforming what could seem like (I am sure not to those reading this but to the unwitting, yet well bent, ears of my family and friends) stories of slightly boring data collecting trips (their patience on the discussion of leaf hairiness is, I fear, dwindling) into tales of days out where I felt akin to John Muir exploring a wilderness in all its fecundity for the first time.

John Muir, it has to be said, was inarguably a rather better navigator than I, even without the smartphone, GPS and laptop that were at my modern adventurer’s disposal. As the trees that I was collecting from were predetermined, having been genotyped in a previous stage of the project, their coordinates were noted, I had their locations shown on a satellite image using Google Earth and had a gps file with preloaded waypoints. If all I had had to find them were some dots on an OS map and a compass I – I am sorry to say – would probably still be wandering around in the wilderness as I write this. Perhaps this points to an unfortunate symptom of my generation but I rather like to think it just shows how fortunate we are nowadays in having the ability to find even a single tree in dense woodland with pinpoint accuracy and – relative – ease.

There is an argument to say that all this technology takes some of the beauty and romanticism out of exploration. Perhaps that has some degree of truth – but perhaps…even more so, there is beauty in how accessible exploration has become. With the advent of widespread smartphone ownership and readily available apps, it is now easier than ever for people to get involved in field botany. For instance, the app ‘What 3 Words’ divides the world into a grid of 1m ² sections, each with its own unique string of three words: ‘mirroring.disputes.waxing’, for example, when typed into the app, will take you to the exact location of a pure Malus sylvestris at the RSPB reserve in the Wood of Cree. To identify plants, we can use traditional plant keys alongside apps like ‘PlantNet’ – which use a citizen science model to build a database of plants verified by professionals and other users alike – in order to help you narrow down your identifications.

The Tree of Life
So, with all this as only an introduction to the myriad topics to be discussed on apple trees, it is easy to see why Malus invites so much in the way of myth and storytelling. The solitary nature of the European wild apple, and its predisposition to grow on the edge of woodlands and in clearings, really adds a sense of wonder to this magnificent tree. I feel a jolt (don’t laugh) every time I happen upon a lone apple tree while out in the woods, wondering where it came from, who its parents are and how long it has survived. There is a tree near Falloch Falls that in the autumn appears gnarled, lichen covered and ancient, seeming to have shifted to the other side of senescence but for the evidence of a thousand apples carpeting the ground: a truly magical sight.