Hazel | birkin-wildlife

Hazel (Corylus avellana)

Kingdom: Plantae

Division: Magnoliophyta

Class: Magnoliopsida

Order: Fagales

Family: Betulaceae

Genus: Corylus L.

Ecological relationships of hazel

The scientific name is Corylus (authentic Latin but derived from an ancient Greek name korys meaning helmet, a reference to the calyx covering the nut), and it was placed in the birch family Betulaceae, though some botanists split the hazels into a separate family Corylaceae; avellana is thought to commemorate the town of Avella Vecchia in Southern Italy where the nuts were cultivated; hazel is from the Old English haesel. Other synonyms include Common Hazel, Hazelnut, Cobnut. and in Irish it is known as Coll.

Hazel is a native British tree and is common throughout England, Scotland, Wales and Ireland, except for the Shetland Isles, dominating north-western regions, in particular north-east Ireland. It favours oceanic conditions with mild winters as it flowers very

early in the year, although is very susceptible to early spring frosts which are characteristic of these areas (Godwin, 1975). It grows up to altitudes of 610m and is widely distributed throughout Europe except for the far North, inland Scandinavia, Southern Iberia and Balkans, east to Caucasus. Often found as understorey in oak woodlands, up to 1200m. On many subsoils, though preferring chalky, fertile, deep soil. It can form scrub communities on exposed limestone, tending to prefer basic soils, or neutral moderately acidic soils. Natural hazelwoods can be found in the Lake District and in western Scotland although it is not a mountain tree (Wilkinson, 1976). It is not so abundant in north-western siliceous hillside oakwoods, (although not rare) and this is no doubt a result of the absence of coppicing in those parts of the country. Corylus avellana flourishes on calcareous soils and is therefore abundant in the ashwoods on mountain Carboniferous Limestone in Derbyshire, where it often forms pure coppices. It is a frequent constituent of chalk scrub in the south where it can sometimes form the pioneer in colonising grassland (Tansley, 1939) , although it also occurs with conifers. Elsewhere, it occurs in the more fertile, lower-lying parts of the country, usually in association with oak (Quercus spp.), ash (Fraxinus excelsior) and also birch (Betula spp.).

Not acid soils.

Corylus avellana was the first of the temperate deciduous forest trees to immigrate, establish itself and then become abundant in the postglacial period. Its sudden rise to very high pollen frequencies marks the start of the mesocratic phase of the present, Flandrian, interglacial (Birks 1986) and is the first stage in the development of dense, mixed deciduous forest. This Corylus pollen rise is an almost ubiquitous feature of Holocene pollen diagrams and reflects an extremely rapid increase in population (Bennett 1983), probably with no real competition from other taxa and no effective environmental constraints (Birks 1986). Radiocarbon dates for the Corylus rise usually fall between c.9,400 and c.9,000BP, although it occurs later in more environmentally marginal regions such as the uplands and on isolated islands such as Mull and Arran (Innes 1999, Boyd and Dickson 1986). Here the rational pollen limit (rise to abundance) of Corylus occurs more typically from c.8,800 to 8,500BP. Birks (1989) has presented an isochrone map for the Corylus pollen rise suggesting the earliest spread of hazel was through the Irish Sea area, including south and eastern Ireland.

Similar conspicuous increases in Corylus pollen values occurred in previous interglacials but were less pronounced and occurred later in the interglacial cycle than in the Flandrian (West 1977, 1980). Huntley (1993) has considered the possible reasons for the rapid early Holocene expansion of Corylus. He concludes that the greater climatic tolerance of Corylus gave it an advantage over other thermophilous trees like Quercus and Ulmus in the more seasonally extreme climates of the early Holocene. Other factors such as the location of its glacial refugia (Deacon 1974), faster migration rates and the possible effects of Mesolithic human activity (Smith 1970) are judged less likely to be responsible. The early Holocene spread of Corylus avellana has been discussed in detail by Tallantire (2002). Corylus abundance was reduced after several centuries by the immigration and spread of Quercus and Ulmus. Because the large nuts are not dispersed over great distances by small mammals, this has led to speculation that Mesolithic peoples may have transported the nuts with them as a food source, and thereby aided the expansion of the tree's range

Hazel produces pollen in great quantities and also flowers at an early stage in the year giving it increased pollination advantage, resulting in over representation in pollen counts. However, under a heavy oak-elm tree canopy it flowers very little and then the bulk of hazel pollen may result from bushes growing at the woodland margin and in clearings. Moderate Corylus values in mid-Holocene pollen diagrams suggest it mainly grew as a shade-tolerant woodland understory shrub. Exceptionally, Corylus abundance continued in areas of favourable geology such as the limestones of parts of northern England (Bartley et al. 1976) or western Ireland (ref). Corylus is heliophytic and is favoured by forest opening. Very high Corylus pollen percentages are often recorded following the creation of woodland clearings. In the early and mid-Holocene these are often associated with charcoal, as hazel is more fire resistant than most other trees, and have been attributed to the effects of Mesolithic activity (Simmons 1996). Corylus pollen, wood, and fruits have been commonly identified in Late Quaternary deposits and the distinctive nuts of hazel are often recovered from British peat and alluvial sediments. They preserve well in waterlogged conditions, where they have been incorporated in such great quantities that hazel's former abundance seems certain. Sub-fossil nuts show teeth marks of rodents where they have been hoarded and some preserved nut distributions suggest former shoreline detritus of streams and ponds (Godwin, 1975). Hazel nuts remain viable in water for lengthy periods and Birks (1989) suggests that water currents may have been a main long-distance transport agent of Corylus in the early Holocene. At many prehistoric human settlements hazelnuts occur in large quantities, suggesting that they were collected for food. The distinctive microscopic anatomy of hazel wood allows definite identification of well-preserved specimens of wood and charcoal. The wood has been found in the Somerset peat levels, where Neolithic track-ways occur constructed of parallel, straight rods, 3-4m long and shown by annual rings to be 8-17 years old (Coles ref). This suggests early coppicing and hazel rods were used in the construction of many types of artifact, such as fence lines and fish traps (Coles ref). Hazel is palatable to sheep but not cattle and unlike other tree and shrub species hazel does not appear to have been adversely affected by the onset of Neolithic clearance and farming, after which its pollen frequencies generally increased.

Corylus avellana is particularly common in coppice form (Rackham 1980), constituting a natural under-storey in oak and ash woodlands. It is habitually coppiced at approximately 10-12 year intervals especially in south-east England, forming the coppice with oak standard formations characteristic of English woodland. Today, most of these shrub layer communities have been planted and are almost purely hazel, but it is so abundant that traditionally it probably also dominated the under-storey. It also can become locally extensive in roadside and streamside scrub in the north and west of Britain (Godwin, 1975). This makes sense of the fact that one of the ancient names for Scotland was "Caledonia", meaning Hill of the Hazel ('Col' or 'Cal' is the Celtic word for Hazel and 'dun' means hill - as in our modern 'dunes').

Hazel is a large, spreading, deciduous shrub or small tree, reaching a height and spread of 8m (24ft) in 10-20 years, commonly found in the under-storey of damp oakwoods, and sometimes can dominate the shrub layer of ash woods (Rodwell 1991), today often in abandoned coppice form. Diameter: 10-20 cm, usually with multiple stems and a spreading habit. It is hardy, moderately shade-tolerant and grows best on heavy but well drained soil and is also an important component of the hedgerows that were the traditional field boundaries in lowland England. The wood was traditionally grown as coppice, the poles cut being used for wattle-and-daub building and agricultural fencing. As a tree its maximum life span is about 60 years but when constantly coppiced back it can survive 600 years and still produce a good crop of poles. The tree is often regarded as an understory shrub, but does not flower and fruit without sunlight, so is really a canopy tree of woodland edge and clearings.

The Common Hazel however it is often described as a bush rather than a tree, as it tends to produce several 'trunks' or shoots rather than just one. The light brown to grey-brown bark is shiny and smooth, and soon raised in small speckles of spongy light brown lenticels, curling strips which tend to peel away in horizontal strips acting like pores which draw apart the bark allowing the tree to breathe, and the trunks are often covered in mosses, liverworts and lichens, especially in the wetter parts of its range.

The twigs are covered in short hairs. The shoots are pale brown, covered in long, stiff hairs with swollen tips ("glandular"). the bud is ovoid and smooth.

The leaves do not grow until April. The leaves of the Hazel grow quite large, reaching 10 × 10 cm, and are slightly heart-shaped with toothed edges rounding into a long point. They are alternate, simple, rounded, with double-serrate margins, orbicular or obovate, cordate base, sharp, triangular, unequal teeth; harshly hairy, deep green above, softly white-haired on veins beneath. In the bud they are folded into several longitudinal plaits. Petiole stout, densely glandular-pubescent, 1.5 cm they turn yellow before falling in October. The leaves open in early spring growing singly on a short stem, at which time they tend to be lime-green in colour and are bright and pleasing. During the summer they turn from mid-green in colour to tints of green, yellow-brown and pink in autumn. The leaves stay with the tree much longer than most other trees, sometimes well into December by which time they turn to shades of yellow, dull orange and red.

The flowers are produced very early in spring before the leaves, and are monoecious. Male and female flowers grow on the same plant. The male flowers are in the form of pendulous pale yellow catkins 5-7 cm long, which are known as 'lamb's-tails' and first appear as minute sausage-shaped buds of a dullish

brown colour. As they mature they turn a pale greenish-yellow or primrose colour and when its pollen has been shed to green. The catkin consists of a number of bract-like scales each bearing eight anthers on its inner surface; from these fine-grained yellow pollen is shaken by the wind, after which they are discarded. They open in February, a time when most other trees are leafless, and are one of the first harbingers of spring. The female flowers appear on the same branches as catkins, they are grouped in little egg-shaped buds that sit sessile on the branch, and are small red tufts 1-3 mm long on swollen bud-like structures, and it is these that develop into hazel nuts after fertilisation. The flower itself is a two-chambered ovary surrounded by a velvety cup-like bract, which later grows into the large leafy husk or cupule of the nut. It is surmounted by a short style with two long crimson stigmas forming a tassel at the top of the cluster.

Pollination of hazel is by wind, and only takes place between different trees (a tree cannot pollinate itself). The pollen is a smooth, 3-pored, grain with a sub-triangular polar view and sub-oblate equatorial view (Godwin, 1975). The surface sculpturing is faintly rugulate, with tiny scabrae on the ridges (Moore, et al. 1991) but usually appears smooth after preparation. The grain is very similar to Myrica gale (sweet gale) and the two are difficult to separate (Edwards 1981), often shown on pollen diagrams as a composite Coryloid curve. Myrica is more robust with a thicker exine and more pronounced pores.

The fruit of the Hazel tree has a peculiarity in its growth that is worthy of note. The male flowers or catkins are mostly produced on the ends of the year's shoots, while the female flowers are produced close to the branch where they are completely sessile or un-stalked. In most fruit trees when a flower is fertilized the fruit is produced in exactly the same place, but with the hazelnut a different arrangement takes place. As soon as the flower is fertilized it starts away from the parent branch and a fresh branch is grown bearing the new leaves and nuts at its end, thus the new nut is produced several inches away from the spot on which its parent flower originally grew.

The nuts obtained from the Common Hazel (Corylus avellana) are the common edible hazelnuts. They grow in groups of up to four from August and reach 1-2cm in size, compressed ovoid, and are sheathed by an involucre (husk) which partly to fully encloses the nut, whitish green ripening pale pink-brown, in green involucre of two bracts overlapped, 1cm long with teeth 3-5mm deep, sparse long white hairs. The shape and structure of the involucre are important in the identification of the different species of hazel. The nuts ripen to a brown colour in September and October, with the nut itself enclosed by a tough woody shell. Empty nuts are an occasional occurrence.

The English name for this tree derives from the Anglo-Saxon 'haesel knut'; haesel means cap or hat, and refers to the papery cap of leaves on the nuts.

Birds, in particular nut-hatchers (a variety of small passerine birds of the family “Sittidae”) are partial to the nuts, wedging them in crevices and beating at them with their beaks until they crack. Most of the nuts are consumed by these dispersers, but some of those which are hoarded for winter, or are overlooked, germinate and grow the following spring. Left un-eaten the nuts fall to the ground where they germinate. After the winter their shells crack and from it springs a root followed by a new stem still joined to the nut and drawing sustenance from it by two thick fibres. As the root grounds into the earth and becomes established, the stem rises and a new sapling is born.

The nut is rich in fatty oils and vitamins. Weight for weight they contain 50% more protein, 7x more fat and 5x more carbohydrate than hen's eggs.

Composition>Seed (Dry weight)#In grammes per 100g weight of food:

Water: 0 Calories: 650 Protein: 16 Fat: 60 Carbohydrate: 20 Fibre: 4 Ash: 2.8

#In milligrammes per 100g weight of food:

Calcium: 250 Phosphorus: 400 Iron: 4 Sodium: 2.1 Potassium: 900 Thiamine: 0.3 Riboflavin: 0.5 Niacin: 5.3 VitaminC: 6

Some nuts that are hoarded may germinate, and so these animals aid in the dispersal of the hazel.

Hazels are used as food plants by the larvae of various species of Lepidoptera as seen below.

Hazel has been employed by humans for a variety of uses during the past 6000 years. White to reddish, tough and flexible hazel poles, which result from coppicing, can be split lengthways, and can be twisted without breaking. They were used during the Neolithic to make wattle (hazel strips woven into a lattice), for the construction of wattle and daub houses. Wattle fencing has been used in more recent times as sound screens beside motorways and as scenic, rustic windbreaks in gardens.Used in past for cask hoops, basketry, hurdles, thatching, spars, sways and pegs. Hazel wood was (and still is) used to make staffs, crooks, and walking sticks. It is also the wood of choice for divining rods. Hazel leaves were used to feed cattle, and hazelnuts were an essential part of the diet of prehistoric humans. In Celtic mythology, hazel nuts were believed to represent concentrated wisdom.

The tough and flexible branches were considered by some to produce the worst-biting 'birch' rods (the official name, even though referring to another species).

Propagation and growth: From seed - dispersion aided by animals. Easily grown from nuts kept cool and moist till spring.

This large shrub is grown extensively for its nuts. These were produced from pruned bushes grown in open conditions like a fruit orchard.

Nuts are also harvested from some of the other species, including the Filbert, from the closely related Balkan species Corylus maxima.

The nuts are edible and rich in oil, though the variety usually found in cultivation in Britain is Corylus maxima, or Cobnut. The oil is multi-usable and has been employed for cooking or dressing salads, as well as in oil paints, as a machine lubricant and in making perfumery and cosmetics. The whole seed can be used to polish and oil wood. It is very easy to apply and produces a nice finish.

Hazel has long been a favourite wood from which to make staffs, whether for ritual Druidic use, for medieval self defence, as staffs favoured by pilgrims, or to make shepherds crooks and everyday walking sticks. In the case of the latter two, the pliancy of the hazel's wood was used to bend the stems into the required shape, though it was also customary to bend the hazel shoots when still on the tree to 'grow' the bend into a crook or walking stick. The wood readily splits lengthways and bends easily, even right back on itself, which makes it ideal for weaving wattle hurdles for use as fencing or as medieval house walls when daubed with mud and lime. Hazel stakes bent to a U-shape were also used to hold down thatch on roofs. Like willow, young coppiced hazel shoots were used to weave a variety of baskets and other containers. Forked twigs of hazel were also favoured by diviners, especially for finding water. Hazel leaves are usually the earliest native ones to appear in spring and often the last to fall in autumn, and were fed to cattle as fodder. There was also a belief that they could increase a cow's milk yield.

In days gone by hazelnuts would have provided a plentiful and easily stored source of protein, and they were often ground up and mixed with flour to be made into nourishing breads. Cultivated hazelnuts called filberts take their name from St Philibert's Day on 20 August, the date by which hazelnuts were supposed to start ripening. Holy Cross Day on 14 September was traditionally given as a school holiday for children to go nutting, a custom which persisted in England until the First World War. Various places celebrated Nutcrack Night sometime during November, when the stored nuts were opened, though apparently some parishioners were in the habit of taking hazelnuts to church on the following Sunday to be cracked noisily during the sermon. Today hazelnuts continue to be eaten, though more frequently in luxury foods such as chocolate and as hazelnut butter, and as a Christmas delicacy. Woodland crafts using hazel are also enjoying a resurgence, and hazel wattle hurdles have even been used as sound screens along motorways.

To ensure a steady supply of hazel rods and sticks, bushes were or are still are coppiced or cut back to ground level and new growth springs up from the bases or stools. The management of hazel coppice and "coppice with standards" is a precise and ancient science. Traditionally coppice would be cut on a 7-15 year rotation and the woodland divided into the same number of sections as years in the rotation so one part of the wood was harvested every year.

Coppiced Hazel poles were woven into panels called wattles, which were used to construct the walls of houses. Wattles were covered with daub to keep out wind and rain. Daub is a cocktail of wet clay, dung, chopped straw and lime.

Untreated woven panels were used as hurdles to pen sheep and this art is still alive in lowland Britain.

Throughout Britain, there has been a prolonged decline of traditional forms of woodland management, particularly coppicing. At present, however, this ancient woodland skill is undergoing a revival in many areas. This species has been rather neglected in terms of conservation when compared to other native trees. However, its importance has now been recognised, and steps are underway to conserve this species.

Do hazels eventually die, or do the stools get bigger?

We know that where oak has been coppiced over many centuries, the resulting stool enlarges, with individual coppiced trunks forming a sizeable ring around an open central

space (Quelch 2001).From observations particularly at Ballacuan Hazelwood, but also on Mull, we have seen what we believe are hazel ‘rings’ - a bit like the fairy rings formed by fungi in old meadows. These are best developed on gentle slopes or flat ground in the intermediate zones, between the exposed slopes and the sheltered, deep soils on damp ground. Are these evidence of ancient hazel coppice?

At Ballachuan and on Mull, there are examples of circles of ‘satellite’ stools around an empty space, which can measure from 1.10 m in diameter to 2.30 m. (Coppins & Coppins 2000a,b). Intermediate stages of this open circle formation were also detected. About the same time that we were pondering over the implications of this, Peter Quelch was photographing similar hazel stool rings in Scandinavia, and tentatively coming to the same conclusion: that these satellite stools may have evolved through a gradual outward expansion of new stems at the edge of a ‘mother’ stool until a point is reached whereby the centre of the stool becomes too shaded, and central stems are not able to replenish this space, due to canopy shade from the outer, more vigorous stems. The root stock at the centre of the stool may also become exhausted.

The potential extrapolation of this method of vegetative reproduction has interesting implications if taken to logical conclusions; whole series of rings of satellite stools could perhaps be plotted, many overlapping with adjacent rings, and satellite stools themselves could in turn, eventually become ‘mother’ stools, and form further rings. Genetically-related groupings could be traced and plotted, which could lead to conclusions about the ecological history of the stand. Where hazel reproduces by seed, there will be genetic variability, but where it reproduces vegetatively (by spread of stool area or by layering), then is it possible that some hazel stands may represent genetic relics that originated thousands of years ago? In an extensive hazelwood such as Ballachuan (27 ha), the implications of such long-term stand integrity go some way to explaining why this site today is of international importance for its lichen flora.

Of course hazel has been extensively utilized by man over the centuries, as is demonstrated from the archaeological Wetlands Project carried out on the Somerset Levels (Coles & Coles 2001). Several wooden trackways were laid across marshy ground in prehistoric times between the Polden Hills north to high ground at Westhay and Meare. One of these trackways is dated to 2,900 BC (around 5,000 years ago) and is late Neolithic. It is constructed of hurdles woven from hazel. Approximately 1,000 hurdles were used, and later repairs were added with further hurdles (Brunning 2001). Careful analysis of the stems that were used to construct the hurdles revealed that although they are all of a similar diameter, they are not of a similar age, and it was proposed that the individual hazel stems were cut on a selective basis (by drawing), from stools, rather than as a result of complete coppicing (Morgan 1982)

This practice has several advantages:

it reduces the effort of cutting a complete stool simply to obtain the few stems of the required size. Conceivably, though, the un-used cut wood could be used as fire-wood.
leaving the stool more-or-less intact, would stimulate new stems to grow quickly, and straight, up to the light to the gaps in the canopy left by the selective cut. This would mean that the stool could be selectively cut again at an earlier time, even the next year, when stems too small for the first year would have thickened up. Whereas, complete coppicing requires a gap of at least seven years before the complete new growth is sufficiently developed into straight-grown stems, suitable for hurdle making. The stems remaining in the stool would afford some protection from browsing animals.
Selective cutting (or Drawing) would reduce the distance involved in walking to new locations to find suitable stools for the next round of hurdles.
Selective cutting would ensure that the older stems were still present, and these are the nut-bearing stems, providing an important additional food source for late autumn.
Selective cutting would ensure that nearby stands of hazel were retained as shelter for flocks in the winter (not relevant perhaps in Neolithic times, but certainly an important feature and requirement for later farming communities).

Ecological relationships of hazel

Feeding and other inter-species relationships Associated with Corylus avellana:

Food plant of

is foodplant of larva Curculio nucum - Nut Weevil (Coleoptera: Curculionidae) Bullock, J.A., 1992
is foodplant of larva Rhynchaenus avellanae - a weevil (Coleoptera: Curculionidae) Bullock, J.A., 1992

Associate of

is associate of Hypulus quercinus - a false darkling beetle (Coleoptera: Melandryidae) Bullock, J.A., 1992
is associate of Strophosoma melanogrammum - Nut Leaf Weevil (Coleoptera: Curculionidae) Bullock, J.A., 1992

Bark

bark may house hibernating naked prepupa Allantus coryli - a sawfly (Hymenoptera: Tenthredinidae) Benson, R.B., 1952

Bud

bud is galled by Eriophyes avellanae - Big-bud Of Hazel (Eriophyidae) Stubbs, F.B. (Editor), 1986

Cambium

cambium may contain larva Dryocoetinus alni - a bark or ambrosia beetle (Coleoptera: Scolytidae) Bullock, J.A., 1992
cambium may contain larva Triotemnus coryli - a bark or ambrosia beetle (Coleoptera: Scolytidae) Bullock, J.A., 1992

Leaf

leaf (petiole) may house ovum Hemichroa crocea - a sawfly (Hymenoptera: Tenthredinidae) Benson, R.B., 1958
leaf (several leaves) may have rolled larva Byctiscus betulae - Hazel Leaf-roller (Coleoptera: Attelabidae) Morris, M.G., 1990 Bullock, J.A., 1992
leaf is grazed by larva Cryptocephalus labiatus - a leaf beetle (Coleoptera: Chrysomelidae) Bullock, J.A., 1992
leaf is grazed by larva Cryptocephalus nitidulus - a leaf beetle (Coleoptera: Chrysomelidae) Bullock, J.A., 1992
leaf is grazed by larva Cryptocephalus sexpunctatus - a leaf beetle (Coleoptera: Chrysomelidae) Bullock, J.A., 1992
leaf is grazed by larva Gynandrophthalma affinis - a leaf beetle (Coleoptera: Chrysomelidae) Bullock, J.A., 1992
leaf is grazed by larva Altica brevicollis - a flea beetle (Coleoptera: Chrysomelidae) Bullock, J.A., 1992
leaf is grazed by larva Luperus flavipes - a leaf beetle (Coleoptera: Chrysomelidae) Bullock, J.A., 1992
leaf is grazed by larva Allantus coryli - a sawfly (Hymenoptera: Tenthredinidae) Benson, R.B., 1952
leaf is grazed by gregarious larva Hemichroa crocea - a sawfly (Hymenoptera: Tenthredinidae) Benson, R.B., 1958
leaf is grazed by larva Nematinus acuminatus - a sawfly (Hymenoptera: Tenthredinidae) Benson, R.B., 1958 [single record in Ireland]
leaf is grazed by nocturnal larva Tenthredo fagi - a sawfly (Hymenoptera: Tenthredinidae) Benson, R.B., 1952
leaf may have rolled larva Apoderus coryli - Hazel Leaf-roller Weevil (Coleoptera: Attelabidae) Morris, M.G., 1990 Bullock, J.A., 1992
leaf may have rolled larva Deporaus betulae - Birch Leaf-roller (Coleoptera: Attelabidae) Morris, M.G., 1990 Bullock, J.A., 1992
leaf may have rolled larva Pamphilius fumipennis - a sawfly (Hymenoptera: Pamphiliidae) Benson, R.B., 1951

Wood

wood may contain larva Agrilus angustulus - a jewel beetle (Coleoptera: Buprestidae) Bullock, J.A., 1992
wood may contain larva Agrilus laticornis - a jewel beetle (Coleoptera: Buprestidae) Bullock, J.A., 1992
wood may contain larva Trachys minuta - a jewel beetle (Coleoptera: Buprestidae) Bullock, J.A., 1992 b

Dead wood

rotten wood may house hibernating naked prepupa Allantus coryli - a sawfly (Hymenoptera: Tenthredinidae) Benson, R.B., 1952

Until recently hazel has received less conservation attention than some other tree species, but this is changing now that its importance has been recognised.

Coastal Hazelwoods and their Lichens by Brian and Sandy Coppins

http://www.treesforlife.org.uk/tfl.hazel_coastal.html

Because of its growth as a densely-branched understorey component in forests, hazel plays a significant role in increasing the vertical structure within woodland, which is important for bird diversity. Hazel leaves are eaten by roe deer (Capreolus capreolus) and red deer (Cervus elaphus), and the nuts, which are rich in fats and protein, are eaten by the wood mouse (Apodemus sylvaticus) and the red squirrel(Scuirus vulgaris). Squirrels split the shell of the nut in two halves to get the kernel inside, whereas wood mice will gnaw a hole through the shell. In England, hazel is an important tree for the dormouse (Muscardinus avellanarius), but this species is absent from Scotland.

Unlike trees such as birch, hazel has relatively few insect species associated with it. However, there are 5 species of moths which are specialist feeders on hazel, including a narrow-winged leaf miner (Parornix devoniella), whose larvae live under a folded down leaf edge, and a nepticulid moth (Phyllonorycter coryli), whose larvae form 'blotch' mines in the leaves. A few beetles, especially weevils, and some flies are also known to use hazel, while there is a range of insects associated with the nuts, particularly in continental Europe.

Hazel normally occurs as an understorey component in deciduous forests characterised by oaks, ash or birch. However, in comparison to oak and birch it has relatively few mycorrhizal relationships with fungi - only 21 species of fungi are recorded as having this mutualistic association with hazel. Of these, one species, the fiery milk mushroom or hazel milk-cap (Lactarius pyrogalus) is largely restricted to growing with hazel.

Hazel is important, however, in providing the main habitat for an ascomycete fungus (Hypocreopsis rhododendri) which was only known from rhododendrons in North America until it was discovered on hazel in Mull in the 1970s, and then elsewhere in western Scotland. It mainly grows on standing dead stems of hazel, but also has been found on living branches. Because of its rarity in Britain, a Species Action Plan has been prepared for this fungus.

Hazel is very important for lichens, and is the best host species in the UK for Graphidion lichens - those which grow on smooth-barked trees. Several of these lichens are rare and endangered, and are the subject of Species Action Plans, including one (Arthothelium macounii) which is the only host for a parasitic fungus (Arthonia cohabitans). Another lichen (Graphis alboscripta) is also almost entirely restricted to hazel, and is only known from Scotland. Hazel is also a good host for the Lobarion group of lichens - the larger, leafy lichens, which include tree lungwort (Lobaria pulmonaria) - particularly in western Scotland.

The lichens inhabiting the hazelwoods form two broad phytogeographical categories (alliances) - the Lobarion pulmonariae ('Lobarion') and the Graphidion scriptae ('Graphidion'). The Lobarion, in its various facies, is the climax, lichen-dominated community of deciduous trees of old forests in temperate regions, whereas the Graphidion comprises crustose lichens that often predominant on smooth bark where establishment of the Lobarion has been prevented or not yet occurred.

Diseases of European Hazelnut (Corylus avellana L.)

Jay W. Pscheidt and Jeffrey Stone, primary collators (last update 7/21/01)

BACTERIAL DISEASES

Bacterial blight
Xanthomonas arboricola pv. corylina (Miller, Bollen, Simmons, Gross & Barss 1940) Vauterin, Hoste, Kersters & Swings 1995
Bacterial canker
Pseudomonas syringae pv avellanae Psallidas 1993
Crown gall
Agrobacterium tumefaciens (Smith and Townsend 1907) Conn 1942

FUNGAL DISEASES

Anthracnose
Piggotia coryli (Desm.) Sutton
= Monostichella coryli (Desm.) Hohn.
= Gloeosporium coryli (Desm.) Sacc.
= Labrella coryli (Desm.) Sacc.
Armillaria root disease Armillaria spp.
Borro sec
Cryptosporiopsis tarraconensis Gene, Guarro & Figueras
Cytospora canker
Cytospora spp.
Eastern filbert blight
Anisogramma anomala (Peck) E. Müller

Kernel molds

Mycosphaerella punctiformis (Pers.:Fries) Starb. [teleomorph]
Ramularia sp. [anamorph]
Phomopsis spp.
Septoria ostryae Peck

Kernel spot

Nemataspora coryli Peligon
Leaf blister
Taphrina coryli Nishida

Leaf spots

Anguillosporella vermiformis (Davis) Braun
Asteroma coryli (Fuckel) Sutton
Cercospora corylina Ray
C. coryli Montemartini
Mamianiella coryli (Batsch ex Fries) Höhn
Monochaetia coryli (Rostrup) Allescher
Mycosphaerella punctiformis (Pers.:Fries) Starb. [teleomorph]
Ramularia sp. [anamorph]
Phyllosticta coryli Westend
Ramularia coryi Chevassut
Septoria ostryae Peck
Sphaceloma coryli Vegh & Bourgeois
Nectria canker
Nectria ditissima Tul.
Texas root rot
Phymatotrichopsis omnivorum (Duggar) Hennebert

Powdery mildew

Microsphaera coryli Homma
M. ellisii U. Braun
M. hommae U. Braun
M. verruculosa Yu & Lai on various Corylus sp.
Phyllactinia guttata (Wallr.:Fr.) Lev.
= P. suffulta </ul>

Rust

Pucciniastrum coryli Komarov

VIRAL DISEASES

Hazelnut mosaic
genus Ilarvirus, Apple mosaic virus (ApMV)
genus Ilarvirus, Prunus necrotic ringspot virus (PNRSV)
genus Ilarvirus, Tulare apple mosaic virus (TAMV)

PHYTOPLASMAL AND SPIROPLASMAL DISEASES

Filbert Stunt
unknown, suspect a phytoplasma
Hazelnut Yellows
phytoplasma(s)

MISCELLANEOUS DISEASES & DISORDERS

Blanks
empty nut shells, cause unknown
Brown Stain
brown liquefied portions of shell and kernel, cause unknown
Catkin Blast
deformed catkins, cause unknown
Sun Scald
high temperature
Wet Feet saturated soil conditions for extended periods.

Folklore and Legend

In folklore, a hazel rod protected against evil spirits and was the best twig for water divining. In Ireland, it was the tree of knowledge and in medieval England was a symbol of fertility. Hazel nuts were carried as charms or to ward off rheumatism in some parts of England. Before the second World War, it was still quite common for people to harvest the nuts. Like many other rural customs, this was often a communal affair with whole villages going out and about. Timing is very important. Too early and the nuts will lack taste and will not store long. Too late and the jays and squirrels will have all. People would take picnics and a drink of ale or cider. "Nutting" used to be a euphism for "courting", and this expression may originated in the fact that gathering nuts in the woods and shrubland gave lots of opportunity for making contact with the object of one's affection.

Until quite recently young lovers roasted hazelnuts over fires at Hallowe'en, which was also known as "Nut-crack Night." The way they burnt steadily together or flying apart - foretold course of their relationship in the coming year. This custom is an example of the connection between hazels and love, which is very ancient. An old Fenian story tells how Maer, the wife of one Bersa of Berramain, fell in love with Finn and tried to seduce him with hazel-nuts from the Well of Segais bound with love charms. Finn refused to eat them, pronounced them "nuts of ignorance" rather than nuts of knowledge and buried them a foot deep in the earth. Country folklore has always linked the nuts with fertility. An old fabel proclaims that a girl who goes nutting on Sunday will meet the Devil and have a baby before she can wed. This recalls the ballad of Hind Etin, in which May Margret goes on to become the tree-guardian's wife and eventually has seven children by him. In 19th century Devon, an old woman traditionally greeted a new bride with a gift of hazels for fertility in the same way that rice or confetti is used today. ln English villages country-dwellers associate a prolific show of hazel catkins with the advent of lots of babies, and late as the 1950s, the saying, "plenty of catkins, plenty of prams" was taken quite seriously.

Of old, Hazel trees were cultivated by the Romans and because they were so plentiful in Scotland, they called Scotland by the Latinized name Caledonia, a term that comes from Cal-Dun, which means “Hill of Hazel”. Hazel was also plentiful in Europe where wild Hazel has grown abundantly since pre-historic times, there its nuts appears to have formed part of the staple food diet of the Swiss lake-dwellers. Another old custom was to use Hazel-twigs to bind vines to stakes. The vines being sacred Bacchus (the Roman god of intoxication and liberation) and any goats found feeding on them were caught and sacrificed to him on spits made of Hazel.

In mythology the Hazel was attributed to the Roman god Mercury (Mercurius), who is associated with the Greek god Hermes. Mercury/Hermes was the messenger of the gods and also the god of commerce, manual skill, eloquence, cleverness, travel and thievery. Of old he was often depicted with a staff or wand of Hazel called a caduceus, and wearing a broad rimed travelling hat and sandals. As the Greek legend has it, when he was only a few hours old he escaped from his cradle and went out in search of adventure. During which time he stretched cords across a tortoise shell and invented the lyre. Later that same evening perhaps feeling hungry, he stole two oxen from Apollo (the god of the sun) and hid them in a cave where he killed them. When Apollo discovered what had happened, Hermes charmed him by playing on his lyre and Apollo allowed him to go unpunished. In gratitude Hermes gave his lyre to Apollo who in return gave Hermes a magic wand, the caduceus, which bestowed wisdom, wealth and prosperity, and turned everything it touched into gold.

Mercury/Hermes as the messenger of the gods could move swiftly through the air and sea. As such the artistic impression of him changed, wings in his hair replaced the broad rimed hat and the sandals became wings at his ankles to aid him as he travelled on the wind. The caduceus was often depicted with two ribbons tied to it indicting speed as he flowed through the air. Later the ribbons changed to serpents as the caduceus was adopted by the medical profession and became the symbol of the healing arts. The two serpents entwined around the staff are symbolic of illness and health, and life and death, for in ancient symbolism the venom of a snake could be used to heal or to poison.

The Hazel is known by the folk names: Coll, the Poets Tree and Dripping Hazel. Its deity associations are with: Mercury, Hermes, Thor, Mac Coll, Aengus, Artemis and Diana. Its ruling planets are the Sun and Mercury. Its associated element is Air, but it also has a great affinity with Water. Its gender is masculine. It is used to attract the powers needed for: Protection, Fertility, Luck, Anti-Lightening, Wishes, Inspiration and anything associated with the element Air.

The Hazel used to be the only proper edible Nut tree in Northern Europe and this gave it a special place in folklore and tradition. The nut was seen as powerful symbol of Wisdom. "All in a nutshell." Wisdom comes from the old Anglo-saxon root "wissen" which has a double meaning of 'knowledge' as well as 'growing'. Wisdom was seen as "growing power", it was seen as a living process rather than 'dogma'.

It is said to be the quintessential Celtic tree because of its legendary position at the heart of the Otherworld. The Celts equated hazelnuts with concentrated wisdom and poetic inspiration, as is suggested by the similarity between the Gaelic word for these nuts, cno, and the word for wisdom, cnocach. There are several variations on an ancient tale that nine hazel trees grew around a sacred pool, the well of Wisdom, dropping their purple nuts into the water to be eaten by some salmon (a fish revered by Druids) which thereby absorbed the wisdom and send the husks, floating downstream. The number of bright spots on the salmon were said to indicate how many nuts they had eaten. In some accounts, the hazel-nuts cause bubbles of "mystic inspiration" to form on the surface of the streams that flow down from the well. Those that eat the nuts (or the salmon) gain poetic and mantic powers. Many early Irish tales describe poets and seers as "gaining nuts of Wisdom", which is most likely a metaphor for such heightened states of consciousness, aIthough the more literally-minded have argued that this expression could refer to a potent brew made from hazels that hod psychotropic effects. As to this theory, there are numerous references to drinking "hazelmead" in early Irish literature and many references to Scottish druids eating hazelnuts to gain prophetic powers. The hazel's association with wisdom extends to other cultures of the ancient world. In Norse mythology it was known as the tree of Knowledge and was sacred to Thor, and the Romans held it sacred to Mercury, who, especially in his Greek form, Hermes, was the personification of intelligence. Hermes' magic rod may have been made from hazel. The English word derives from the AngloSaxon 'haesl' which originally signified a baton of authority.

In an Irish variation of this legend, is a description of Connla’s Well, believed to be the source of the River Shannon. The well is surrounded by nine Hazel trees which produce both flowers and fruit (beauty and wisdom). As the fruit (the nuts) fall into the well, the salmon that live there eat them and whatever number of nuts they eat, so the same number of spots appears on its body. The salmon also became the recipient of all knowledge. The Hazel’s association with the element Air and speed of movement, is also replicated through its association with salmon, for salmon swim swiftly through the water and at times can be seen taking huge leaps out of the water appearing to fly through the air. One salmon was the recipient of all these magical nuts. A Druid master, in his bid to become all-knowing, caught the salmon and instructed his pupil to cook the fish but not to eat any of it. However in the process, hot juice from the cooking fish spattered onto the apprentice's thumb, which he instinctively thrust into his mouth to cool, thereby imbibing the fish's wisdom. This lad was called Fionn Mac Cumhail and went on to become one of the most heroic leaders in Irish mythology.

The Gaelic word for hazel is Coll. It appears frequently in place names in the west of Scotland, such as the Isle of Coll and Bar Calltuin in Appin, both in Argyllshire where the tree and its eponymous place names are the most common. It also appears in the name of Clan Colquhoun whose clan badge is the hazel. The English name for the tree and its nut is derived from the Anglo-Saxon haesel knut, haesel meaning cap or hat, thus referring to the cap of leaves on the nut on the tree.

Hazel was an important tree in Irish mythology. It represented the letter 'Coll', which was the ninth letter of the Irish Bardic Ogham alphabet. It gave its name to a God named Mac Coll (son of Hazel), who according to Keating's history of Ireland was one of the earliest rulers Ireland, his brothers being Mac Ceacht (son of the plough) and Mac Greine (son of the Sun). They celebrated a triple marriage with the Triple Goddess of Ireland: Eire, Fodhla and Banbha.

Since mediaeval times trees have been considered sacred. In Ireland in particular three trees gained special prominence, the Apple tree for its beauty, the Hazel for its wisdom and the Oak for its strength. Indeed so sacred were these trees regarded that any unjustified felling of an Apple Hazel or Oak tree carried the death penalty. Through their associations with beauty, wisdom and strength, the wood of these trees was often combined to make funeral pyres. At which times particular respect seems to have been paid to the Hazel in relation to its wisdom, for many cases have been recorded both in England and on the Continent of Hazel-wands being found in the coffins of notables. Among the chiefs and rulers of ancient times, a Hazel wand was considered a symbol of authority and wisdom.

Haze woods frequently figure in the sacred landscape. In Ireland, hazel is coll, and the early triad of Gods of the Tuatha Dé Danaan, MacCuill, (son of HazeI), MacCecht (son of the Plough) and MacGréine (son of the Sun) supposedly divided the island into three so that the country was said to be under the plough, the Sun or the hazel, for "these were the things they put above all other". Tara, the chief seat of the kingship in Ireland was built near a hazel wood, and the great monastery of Clonord was established in what must once have been a sacred Pagan place known as The Wood of the White Hazel: Ross-FinnchuilI . In Scotland, a hazel grove was Calltuin, (modern Scots Gaelic calltainn) and various places called Calton are associated with entrances to the Otherworld, one being the famous Calton Hill between Leith and Edinburgh, which Was probably still being used for magical gatherings in the 17th century. There is even a legend that St. Joseph of Arimathea built the original abbey of Glastonbury from hurdles of hazel branches.

The hazel's connection with the Well of Wisdom is visibly recalled by the tree's frequent presence at holy wells throughout Britain and Ireland, where pilgrims still continue to festoon its branches with votive offerings in the form of pieces of cloth. Moreover archeologists have found early Celtic shaft-well in Norfolk, England which contains offerings of alms, placed in layers and embedded in hazel leaves and nuts.

In the north of England, the hazel-tree guardian was called "Melsh Dick" and in Yorkshire "Chum-milk Peg", ancient protectors of the unripe nuts.

As might be expected from their legendary reputation for bestowing prophetic powers, hazels have been used for divination throughout the centuries. Druidic wands were made from the wood, and it has a always been the preferred wood for water divining and dowsing.

Down through the ages the Hazel has always been considered magical, and was used primarily for its powers of divination. The use of Hazel to detect water and mineral veins comes down from antiquity. Typically a divining rod (dowsing rod) had two forks off its main stem shaped like the letter “Y”. The two forks were gripped in the fists with the fingers uppermost, so that the tail end pointed downward toward the object sought. In other cases the rod was peeled and simply laid on the palm of the hand. Before the 17th century Hazel rods were also used to find thieves, murderers and treasure. The magical power of the hazel still lives today whenever a water-diviner uses hazel-rods to dowse for water. As the rod bends to reveal the water within the earth, it may be that it is also straining to reconnect with ancestors, the nine sacred trees at the Well of Wisdom deep with in the memory of the land.

The art of divination by dowsing is called “rhabdomancy”. According to Evelyn (John Evelyn, 1620-1706. An English author who’s “Diary” (1640-1706) was considered an important source regarding late 17th-cent English politics and religion) the art of rhabdomancy is: "Very wonderful by whatever occult virtue, the forked stick (so cut and skilfully held) becomes impregnated with those invisible steams and exhalations, as by its spontaneous bending from a horizontal posture to discover not only mines and subterranean treasure and springs of water, but criminals guilty of murder etc. Certainly next to a miracle and requires a strong faith." Even Linnaeus (Carolus Linnaeus (orig. Carl von Linne) 1707-78. The Swedish botanist considered the father of modern botany) confessed himself to be half a convert to this belief.</p>

<p>The practice of dowsing is still common today in Cornwall and other western counties. According to local superstition, the rod is guided to water or mineral lodes by guardian piskies, or the kobolds of the German miner. The dowser or rhabdomancer is said to feel a sudden acceleration or retardation of the pulse, or a sensation of great heat or cold at the moment of discovery. Other woods such as the Willow have also been used with success for dowsing.

It is probable from this use of Hazel rods in divination, that the nuts of the Hazel became associated with fortune telling. In Scotland an old custom of love divination still prevails on Halloween, in which two hazelnuts are given the names of lovers and placed on burning embers. If they burn quietly and remained side by side, the lovers were considered faithful, but if the nuts crack, spit and roll apart, they were considered to be ill-matched and one of them unfaithful.

In ritual Hazel wands are used in connection with mercurial energy from which poetic and magical inspiration is gained and imparted. Hazel wands can also be used to divine suitable places in which to work magic. An old method of cutting a wand was to find a tree that has yet to bare fruit, and at sunrise on a Wednesday (the day ruled by Mercury), to cut a branch with a single stroke from a sickle. The Hazel is considered to be at its most powerful during early spring while its sap is rising, and in autumn when its sap and energy is fully contained within it, ready for its harvest of nuts. A good divining rod is said to “squeal like a pig” when held under water.

The nuts of the Hazel were commonly used to bring luck by stringing them together and hanging them in the house. Such a string of nuts were often given to a new bridesmaid as a gift, to wish her good fortune. Eaten the nuts give wisdom and are said to increase fertility. They were also of old, eaten before divination to increase inspiration.

Also of old, supple twigs if Hazel were woven into crowns and called “wishing caps”. When worn and if you wished very hard, your desires would come true. Sailors, believing them to offer protection against bad storms at sea, also wore wishing caps. The ancient druids believed they could induce invisibility by wearing them. Twigs of Hazel placed on window ledges give protection against lightening, and three pins of Hazel hammered into a wall of the house would protect it from fire.

Carrying a double hazelnut in a pocket was and old country charm used to prevent toothache. If bitten by a snake, an equal armed cross made of Hazel laid upon it, was an ancient remedy said to draw out the poison.

An old charm for curing an adder bite requires a piece of hazelwood in the shape of a cross to be placed upon the wound, and the following lines repeated:

"Underneath this hazelin mote,
There's a braggoty worm with a speckled throat,
Nine double is he,
Now from eight double to seven double
And from seven double to six double
and so on until:
And from one double to no double,
No double hath he"

Hazel was also used widely throughout the centuries for protection against evil. Finn bore a hazelwood shield that made him invincible in battle. No harm could penetrate a hurdle fence of hazel around a house or a breastband of the wood on a horse. A shipmaster wearing a cap into which hazel had been woven was guaranteed to weather any storm. Cattle driven through Beltaine and Midsummer bonfires had their backs singed with hazel rods for protection against disease and the evil eye , and the scorched rods were used to drive them the rest of the year. In the East of England, cottagers gathered hazel boughs on Palm Sunday, and placed them in pots of water around their windows as protection against thunder and lightening - possibly a sign of Norse influence in that area, the hazels being used homeopathically against the bolts of the Thundergod. A famous legend tells how the seventh century Saint Mungo was unable to light monastery lamps on a day when it was his duty to do so at cockcrow, because some malevolent boys had put out the fire. He walked out of the monastery in despair, but thought to pluck a hazel switch and when he returned to the church with it, praying for heavenly aid, a fire sprang forth from the branch.

When evil became synonymous with witchcraft in the public mind, hazel was widely used for protection against Witches. The Discovery of Witchcraft (1584) recommends a hazel wand cut "upon the Sabbath day before rising" to use as a charm against witches and thieves. The 17th century writer Thomas Pennant in his "Tours of Wales" described how in Merionethshire, corpses were buried with hazel-rods to avert the power of witchcraft. Hazel protected against disease and was a potent magical remedy besides. ln Ireland, a hazel nut in a pocket worded off rheumatism or lumbago which was thought to be caused by "elfshot," and a double-nut prevented toothache. In the legend of the early Celtic St. Melor, an abbot gathers hazel-nuts and offers them to the saint. On receiving them, his artificial hand becomes flesh and blood.

Astrologically hazel people (i.e. those who are born during the month of July) have the soul of a pioneer, but they waste too much energy on competitive thoughts and fighting abuses instead of letting their own gifts and skills ripen. Hazel people can be impatient for things to happen, and hurry things along when they should sit back and let things take their own course. They are sometimes too intent on running around trying new things, that they forget the older values of patience that would help them. When Hazel people listen to their own natural rhythms, they find they are happier and more prepared spiritually and physically. They are generally charming, undemanding, very understanding and know how to make an impression. They can be active fighters for social causes, are popular but can be moody. They are capricious lovers but are honest and tolerant partners. They also have a precise sense of judgment about what is right and wrong.

Hazel Medicine

Anthelmintic; Astringent; Diaphoretic; Febrifuge; Nutritive; Stomachic; Tonic. The bark, leaves, catkins and fruits are astringent, diaphoretic, febrifuge, nutritive and odontalgic.

The seed is stomachic and tonic.
The Hazel has not been as widely used in herbal medicine as some of our other trees. Nevertheless the dried or fresh leaves have a stimulating effect on the circulation and bile production, as well having some diuretic properties. The leaves have used in the past in some patent medicines for gall and liver disorders. The 17th century herbalist Nicolas Culpepper wrote:
"The parted kernels made into an electuary or the milk drawn from them with mead or honied water is good to help an old cough, and a little pepper put in draws rheum from the head. The dried husks and shells to the weight of two drams, taken in wine, stays laxness and women's courses, the skin answers the same purpose." The oil has a very gentle but constant and effective action in cases of infection with threadworm or pinworm in babies and young children. The finely ground seeds are used as an ingredient of face masks in cosmetics.

Hazel bark has been used as a substitute for Witch Hazel (see below). This must work fine to some extent, since all tree barks contain relatively large quantities of tannins.

The kernels of the nut ground fine and mixed with mead or honeyed water is said to be good for coughs that won’t clear, and when mixed with pepper in a decoction will clear a muzzy head.