The Strawberry Tree { Study of Trees} -19

The Strawberry Tree

Taken in France
Taken in France | Source

Introduction

This is the 19th article in the series a study of trees where the intention is to help those who wish to identify trees but are unsure of the species. Most people commence their identification of trees by recognizing the shape and colour of the foliage. This is fine during the summer months but of little use during the winter when the branches are naked and bare.

However, every tree has a character {s} that will help the observant to recognize the tree species even in the depths of winter. Here we look at the Strawberry Tree Arbutus unedo and with the aid of descriptive text and great images it will enable the reader to recognise the species and learn something of its history.

Tree showing fruits

Source
Uploaded to Commons by MPF
Uploaded to Commons by MPF | Source

About the Strawberry Tree and a little history.

The Strawberry tree Arbutus unedo,referred to by some botanists as Arbutus vulgaris or Unedo edulis, belongs to the order of plants known as the Ericales and the family Ericaceae within that family. This is the heath or heather family whose species tend to form woody stems. Many of its members are moorland,alpine or sub alpine plants,being tough,wiry perennials that have stems of dense wood,though seldom attain any height,bearing leathery evergreen leaves,often of a very small size.

Some, however, such as some Rhododendrons and the Arbutus {the Strawberry Tree},reach the dimensions of a tree,and whilst some members of the Order,for example the Azaleas and Whortleberries,are deciduous, the majority of them,among which are the Heaths, Rhododendrons and Arbutus have evergreen leaves.

They thrive best in peaty soil,and occur on dry Moors in sub-tropical countries, in Swamps and moist uplands further north, in most parts of the world, in fact except absolute deserts on the one hand,and hot damp regions of the tropical jungle on the other, the vegetative structures of the order exhibit typically 'xerophytic' characters, that is, showing they can adapt to a deficient water supply,at least for part of the year.

Of these the leathery texture of the leaves,with thick cuticle.and a small number of 'stomata' or transpiration pores, is the most general of the characters,though in true heathers this is accompanied by the reduction in the size of the leaves and an in-rolling of their edges towards the surface on which the stomata is situated,so as to lessen transpiration still further.

Whilst however, in the true Heaths,no true winter buds are formed. in the sub-division of the Order to which the Arbutus belongs some of the xerophytic characters of the order have, to some extent, been lost by secondary adaptation, such as buds are formed with true bud scales, though the leaves remain on the tree throughout the winter.

The name Arbutus derives from Latin and is related to Arbor a tree. The specific name of unedo is thought to derive from unumedo indicating 'I eat one'.

Evergreens, as our subject is, dread frost and are thus characteristic of warm climates,or, of insular conditions in higher altitudes,where the frost is rare, rather than inhabiting the interior of continents where, through the summer they may be hotter, the winter is also colder. This determines the geographical distribution of Arbutus. Regardless of the characteristics of the soil, it is common all around the Mediterranean,from Syria,Greece,southern Italy,Algeria and Spain, it extends along the coast of Portugal and the Landes of Bordeux as far north as Rochelle, but it appears unable to survive the cold winters of Paris.

Here in the UK it naturalizes easy in the warm moist slopes above the Bristol Avon at Clifton and it is native in Ireland and has long been recorded in the neighbourhood of Killarney. In the latter locality,where it grows to a large size it ripens fruits and increases by self sown seeds. there seems to have been some dispute as to whether the tree was indigenous to Ireland, some say they believe it was introduced by St.Finian at the close of the sixth century, others say by Franciscans who founded Muckaross Abbey in the fifteenth century.

The fruit is eaten by birds which aid the dispersal of the species. The first reference of the occurrence of the Strawberry tree in the British Isles is Parkinson, in 1640. Apart from the countries mentioned above, they occur in south eastern France,Algeria,Morocco and Tunisia,and eastward to Greece,Turkey,Cypress, Lebanon and Syria, they also occur in Bulgaria,Croatia and south western Ireland. In the UK Dunstar Castle includes the National Plant Collection of Strawberry Trees which constitutes the national Arbutus collection.

Components of Arbutus unedo

Pierre Joseph Redoute.
Pierre Joseph Redoute. | Source

Mature trunk of Arbutus unedo

Source

Description of the wood and foliage.

The tree grows to the height of eight to twelve feet generally. Older specimens develop attractive ,twisted and gnarled trunks and branches. The bark is described as being a warm red brown.Its flaking bark is very striking contrasting admirably with the dark glossy green of the leathery leaves.

The foliage is glossy on top , oblong or oval with toothed margins. They are about two tofour inches { 5-10 cm} long. They have been likened to those of the Bay tree, others say they are intermediate between the Oak and Bay Laurels, they also have a superficial resemblance to those of the Rhododendron.

In spring the scales of the buds are shed, the buds open so that a gap is left on the stem between the last year's leaves and those of the coming season, and these are somewhat crowded at the ends of the twigs in a loose rosette.


Close up of the foliage.

Taken in Madrid
Taken in Madrid | Source

The flowers of Arbutus unedo

There is perhaps no Order of plants which show such a variety and beauty of flower form as in Ericacea. It is hard to find appropriate words to describe the exquisite proportions of the Kalmia, Boulger, attempts to do so. " A chalice of snow,studded with rubies or blushing in its own Chastity".

The corolla of the Arbutus is almost equally unique in its particular beauty. Whilst,when the observant eye discovers the contrivances within its cup, the intellect is charmed by the interior as are the senses by its exterior. Theophratus {Classical Greece} describes each blossom so that it is formed like an egg-shell,cut in half,equal in size and form of a long Myrtle blossom.

The flowers according to Parkinson, 1640, are formed like unto little bottles, or flowers of Lilly Convallery { Lily of the Valley}" The flowers are reluctant to appear before September or October, their loose pendulous clusters of creamy bells, as Parkinson said, resembling those of the Lily of the valley but not so white.

Within each bell-shaped corolla, less than half an inch across are ten tiny stamens the central column of the style. The ovary at the base. The ten stamens spring from the base of the corolla tube each consisting of short stout filaments coated with hairs and tapering towards the anthers. The latter consists of two parallel and united ovoid bags,tapering at each end to a blunt point,each having near one extremity a tail-like process projecting from it almost at a right angle,whilst at the other end of the anther, when immature, is a viscid pointed appendage.

The bell shaped flowers of Arbutus unedo

Taken in Madrid.
Taken in Madrid. | Source

Flowers continued

At first the filaments bend outwards towards its base,while the viscid point is cemented low down on the style. A change in direction of growth of the filaments takes place,and they bend inwards towards the style as they lengthen,causing the anthers to revolve through about one hundred and twenty degrees on the point cemented to the style,until their 'tails' point towards the mouth of the corolla tube and their blunt ends are pressed towards the style.

Then when the viscid point has separated from the style and disappeared,a thin membrane closing the end of the anther also disappears,so that the pollen is only kept in as long as the point of the anther is against the style. The pendulous blossoms are much visited by bees,wasps and later butterflies and moths,who,hovering beneath them thrust their proboscis into the bell to gather honey clinging to the hairs of the filament. In doing so the bees must touch some of the twenty tail-like processes which radiate from the style, like spokes of a wheel,and if they do so,will tear open the mouth of the anther away from its contact with that of the central column,when the pollen will fall upon the hairy head and the back of the insect visitor,to be carried to the stigma of the next blossom against which it may run its head.

The fruits are green in the early stages

Source

Fruits ripening

Uploaded to Commons by Magnus Manske
Uploaded to Commons by Magnus Manske | Source

The fruit of the Strawberry tree

The fruit of this species takes up to a year to ripen and so it is often found on the tree when the new buds appear in spring. Parkinson, 1640, states " The round berryes,greene at the first,yellowish afterwards,and of an excellent reddish colour,and somewhat hoary withall being full ripe,like unto a strawberry,but much greater in the naturall warme countries,as great as a plumbe,but with us, and in Ireland,where they have been found growing of their own accord,no bigger than a raspisberrie,and neere unto the same,both forme and colour, that is like a pallid claret wine of an austere taste"

The round berries which succeed these elaborate flowers have a surface projecting in numerous points,more like the fruit of the Litchi,than that of the Strawberry,and when they are fully ripe,which is not for many months after the fall of the carolla, they are orange scarlet,and far better eating than before.

they are divided internally into five chambers each containing four to five seeds. The fruits are edible {when ripe}, they can be preserved,made into wine,jams,beverages and liquers. They are eaten by wild birds. They are also good bee plants for honey production


Fruits of the strawberry tree

Source

Courtesy of EatYourBackyard. Standard You Tube License

Arbutus and the gardener.

The trees in this genus of trees and shrubs are grown for their leaves and clusters of urn or bell-shaped flowers,ornamental bark and strawberry-like fruit,which are edible but many say insipid.

They are frost hardy,but need protection from strong cold winds when young. They prefer to be situated in full sun and they require fertile,well drained soil. They are propagated by semi-ripe cuttings in the late summer or by seed in the autumn.

There are many varieties available to the modern gardener such as the Greek Strawberry Tree Arbutus andrachne. This species can reach the height of twelve metres. The bark is smooth and exfoliating during the summer,leaving a layer of green colour which changes to gradually to a beautiful orange brown. It flowers in late spring. the flowers are urn shaped and white. The foliage is a glossy dark green colour.

Arbutus andrachne The Greek Strawberry tree

Source

Two more species of Arbutus

Arbutus arizonica is commonly referred to as the Arizona Madrone and is native to the south west United States and north west Mexico. It grows up to forty five feet {14m} and has pinkish brown bark. The fruit is an orange -red beery,which is edible.

Arbutus menziesii is an evergreen spreading tree with an height and spread of fifty feet {15m}. It has smooth,peeling reddish bark and oval dark green leaves. They produce large upright ,terminal panicles of urn-shaped white flowers in early summer followed by orange and red fruits. This species requires an acid soil.

Fruits of Arbutus arizonica

Provided by ARS Systematic Botany and Mycology Lab. United States Arizona.
Provided by ARS Systematic Botany and Mycology Lab. United States Arizona. | Source

More by this Author


4 comments

D.A.L. profile image

D.A.L. 22 months ago from Lancashire north west England Author

aviannovice,

Hi Deb,glad you enjoyed it. Best wishes to you.


aviannovice profile image

aviannovice 22 months ago from Stillwater, OK

These are such fascinating trees, and unlike many, they provide food for all. Nice work!


D.A.L. profile image

D.A.L. 23 months ago from Lancashire north west England Author

DDE,

hello Devika, Thank you for being the first to visit and for leaving such encouraging comments. And,once again for all your votes,you are so kind. Best wishes to you..


DDE profile image

DDE 23 months ago from Dubrovnik, Croatia

Hi D.A.L. I have enjoyed reading and learning from all of your hubs. You share such fascinating topics. Voted up, useful interesting and beautiful.

    Sign in or sign up and post using a HubPages Network account.

    0 of 8192 characters used
    Post Comment

    No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.


    Click to Rate This Article
    working