Broadleaved Trees
The broad-leaved trees illustrated on the following pages are Angiosperms, i.e. they bear flowers and the ovules are completely enclosed within an ovary. Further, as they are all Dicotyledons their leaves are net-veined and the embryo within the seed has two cotyledons. These features distinguish them from the other Angiosperm group, the Monocotyledons including the Palms, not considered here which have leaves with parallel veins and a seed embryo with a single cotyledon. There are, very...
Reproduction Of Conifers
The conifers are Gymnosperms and, unlike the broad-leaved trees, their seeds are not enclosed in an ovary. As the name of the group implies, they bear cones. The pollen grains and ovules are always produced on different cones which usually occur on the same tree. Male cones. These are small and consist of a central axis bearing lateral scales which have two to five pollen sacs on their under surfaces. When mature the sacs split open and the dry powdery pollen grains are released. Female cones....
Distinguishing Features
Cone scales become detached Entire leaves shed leaving a smooth disc-like scar on the stem ABIES ALBA Mill. European Silver Fir This species is a native of central and southern European mountains. It is a beautiful tree up to 160 feet high with a smooth grey bark which becomes scaly with age. The young shoots are downy and bear non-resinous buds. The spirally arranged leaves are up to an inch long, flattened, blunt dark green above and whitish below. The solitary erect cones are four to six...
Transverse Section Of A Tree Trunk
The Inside. In this way the stem is continually Increasing in thickness. Xylem. This is the wood, a complex tissue which forms the bulk of a branch or trunk. During each growing season a new ring of xylem Is added owing to the activity of the vascular cambium. The texture of the wood laid down in the spring differs from that formed in the late summer so that these increments of growth can be seen with the naked eye in a cross-section of the trunk. By counting these 'annual rings' a rough...
Botanical Names Of Conifers
pisifera . . 30 Cryplomer a jap nica . . 26 Cupressus am nica 31
Thuja Occidentalis L.
The genera described in this book can be separated t. Leaves scale-like, large, spirally arranged. more or less straight, pointed, Rfl r two to five borne apically on a dwarf shoot. 7. Leaves linear, I inserted singly on the stem. IJ similar to those of broad-leaved trees. on the basis of the form and arrangement of leaves. on the basis of the form and arrangement of leaves. Sequoiadendron, Cryptomeria, Juniperus sabina Thuja, Libocedrus, Chamaecyparis, Cu-pressus Picea, Abies, Pseudotsuga,...
The Names Of Trees
Many of the trees described in this book, both native and introduced, have common English names, in consequence some explanation is necessary for the prominence given to the less familiar scientific names which are difficult to spell and remember. There are several reasons for adopting this course. Firstly, the common names lack precision. To the casual observer a Birch tree is easily recognizable but in fact we have two native species in Britain. Although closely related, so closely in fact...
Vertical Section Of A Stoma
Exerts an upward pull on the water columns present in the vessels of the xylem so that the leaf is continually supplied with water. Parts of the leaf. Basically a leaf possesses a thin flat green blade or lamina borne on a thin staik or petiole. When the petiole is absent the leaf is desciibed as sessile. The lea is attached to the stem by its swollen leaf base. In some species small flattened structures, the stipules, ara present on either side of the leaf base. There is always an axillary bud...
The Flowers
The broad-leaved trees are Angiosperms and produce flowers. Basically a flower possesses a stalk or pedicel terminated by a short receptacle which bears lateral floral organs. From the outside to Hie centre are The caly , consisting of several, usually five, sepals which are often green and protect the flower bud. The corolla, usually consisting of five petals. These are often brightly coloured and may be fused together forming a cup-or funnel-shaped sympetalous corolla. The androecium of few...
The Root System
Being below ground the root system escapes genera atlention but in fact it is at least as extensive as the aerial system we see above soil level. Broadly there are two types of root systems. Some trees have a stout tap root which penetrates deeply into the soil, whereas others have a fasciculate system of several main roots which grow obliquely downwards. However, intermediate types are common and although some trees are typically shallow-rooted and others deep-rooted the depth of penetration...
North American maples
A number of North American species of Acer have been introduced into Britain and are frequently seen in parks and gardensAcer rubrum Reci Maple . This is a deciduous tree reaching 100 feet in height with a smooth whitish bark. The opposite leaves, which are pale underneath, are similar to those of the Sycamore but the lobes are more pointed. They turn bright red in the autumn. The flowers are also red ant 'e wings of the small fruit lie at an acute angle. Acer saccharUm Marshall Sugar Maple ....
Distinguishing Features 1
ULMUS CARPINIFOLIA Gted. Smooth Elm This elm is a native of central and southern Europe and in Britain it occurs mostly in southern and eastern England. It is a variable deciduous tree 70 to 90 feet high with spreading branches and a rough bark, The alternate leaves have short stalks and toothed, pointed blades up to four inches long. The blades are smooth or very slightly hairy above and they are asymmetrical at the base. The pink flowers appear in dense clusters before the leaves unfold. The...
Leaves Alternate
A Margins of leaflets entire gt J pC ' CJadrastis, Gymnocladus, Sophora, Robrnia, Laburnum, Cedrela a' Q b Margins of leaflets finely gt ' toothed r ft C- Ailanthus, Juglanl, Carya, Pterocaryaj Gleditschia, Sorbus c Margins leaflets deeply hj J toothed and sometimes more or Ay y less lobed It- Kcelreuterla, Rhu ''-' ' ' The members of this genus are deciduous trees or sbrubs, mostly tropical, with alternate entire leaves and hard heavy wood. The fruit is a succulent berry with a persistent...
