pin-eyed and the thrum-eyed, the two forms growing on different plants.
The former has its stamens at a contracted portion of the tube, about
half way down, and a style so long that the stigma is visible at the top
of the tube. The latter has its stamens at the contracted throat of the
tube, while the style is so short that the stigma is half-way down.
[Illustration: THE BUGLE.]
These two forms may be termed the long-styled and the short-styled
primrose, respectively, and the difference is of great importance,
inasmuch as it helps to bring about the cross-fertilisation of the
flower.
[Illustration: THE BROAD-LEAVED GARLIC.]
The principal agents concerned in the transfer of pollen from one flower
to another are the wind and insects, but it is evident that the work is
done, in the case of the primrose, by insects; for not only do we find
that the anthers and the stigma are protected from the wind, being more
or less hidden in the tube of the corolla, but the showy corolla, the
delicate scent emitted by the flower, and the nectar produced at the
base of the tube all combine to encourage nectar-loving insects whose
proboscis is long enough to reach the sweets.
While such an insect is sucking the nectar from a short-styled primrose,
the base of its proboscis is rubbing pollen from the anthers at the top
of the tube, and the removal of the pollen is assisted by the contracted
throat of the corolla in this kind of flower. Should that insect then
visit a long-styled flower, the base of the proboscis, now dusted with
pollen, will transfer some of the pollen cells to the stigma. In the
same way pollen will be transferred from the anthers of the long-styled
to the short-styled flower, since the stamens and stigma respectively
occupy corresponding positions in the tubes of the corollas.
[Illustration: THE STAR OF BETHLEHEM.]
On Plate I (Fig. 3) we represent the Lady's Slipper
(_Cypripedium Calceolus_)--a rare and beautiful orchis found in some of
the limestone woods of North England. Its stem is downy and leafy,
reaching a height of about one foot. The leaves, of which there are
three or four, are oblong and ribbed; and the one or two large flowers
are brownish with the exception of the lip, which is yellow and
inflated.
Two species of Garlic (order _Liliaceæ_) are also to be found in woods
early in the season. They are both strong-smelling plants with bulbous
roots, radical leaves, and flowers arranged in an umbel with membranous
spathes. One--the broad-leaved Garlic or Ramsons (_Allium ursinum_)--is
very common, grows to a height of from six to twelve inches, and flowers
from April to June. The stem is bluntly triangular and leafless; and the
broad, radical leaves are much like those of the Lily of the Valley. The
flowers are white, and form a flat umbel with two sharply-pointed bracts
at its base.
The second species--the Sand Leek or Sand Garlic (_A.
Scorodoprasum_)--grows to two or three feet, and is found almost
exclusively in sandy woods of North England, where it flowers a little
later than the Ramsons. The stem-leaves are linear, and form two-edged
sheaths; and the flowers, which are reddish-purple, are in a loose
umbel. (Plate I, Fig. 4.)
[Illustration: THE HAIRY SEDGE.]
The Star of Bethlehem (_Ornithogalum umbellatum_) is a pretty flower
that was originally introduced for cultivation, but has now become well
established as a wild flower in many parts of Britain. It is found
chiefly in copses and thickets, especially in the neighbourhood of towns
and villages, and flowers in April and May. It has an oval bulb
containing an abundance of viscid sap; long narrow, limp, radical
leaves; and a flowering stem from six to twelve inches high. The flowers
are white, from six to ten in number, arranged in a raceme the lower
stalks of which are lengthened in such a manner as to bring all the
flowers to a level, thus giving the general appearance of an umbel.
There is a membranous bract at the base of each pedicel; and each flower
has a perianth of six free, spreading, persistent segments, marked
outside with a central, green line, and having a nectary at the base.
The same order includes the well-known Blue-bell or Wild Hyacinth
(_Hyacinthus nonscriptus_ or _Scilla festalis_), which is occasionally
confused with the Harebell of the order _Campanulaceæ_. The leaves of
this plant are linear and channelled, and the drooping flowers form a
raceme of from six to twelve blooms. The perianth is bell-shaped,
composed of six united parts, usually blue, but rarely pink or white.
The anthers are yellow, and as with all the plants of this order, the
ovary is superior. (See Plate I, Fig. 5.)
In damp woods we often meet with the Hairy Sedge (_Carex hirta_), which
grows from one to two feet high; and in similar situations, the
Pendulous Wood Sedge (_C. sylvatica_)--a tufted species, with a weak,
leafy stem, from two to three feet high, and flaccid leaves. The latter
has a single terminal, male spikelet, of about an inch long; and
slender, drooping female spikelets, of about the same length, on long
stalks.
On Plate I, we also represent the Wood Melic Grass (_Melica uniflora_),
a slender, graceful species which may be seen in woods, often in bloom
as early as the beginning of May.
VI
THE SPRING-FLOWERING TREES AND SHRUBS OF WOODS, THICKETS, AND HEDGEROWS
Having considered the principal low-growing flowers of the woods, we
must now give some attention to the trees and shrubs of the same
localities.
This portion of the field-naturalist's work will be found at least as
fascinating as the observation of the herbaceous plants, for although
the flowers of trees are often small and very inconspicuous, many are
really beautiful blossoms, and all present features of more or less
interest to the botanist. Moreover, the observations of these flowers
will always be coupled with those of the appearance and expansion of the
leaves, for while some trees produce their flowers shortly before their
leaves, and others after, leaves and flowers often come about the same
time, and the period of the year covered by the present chapter--from
about March to April or early June--will include the bursting of the
leaf-buds and the expansion of the leaves of all our deciduous trees and
shrubs. Opportunities should be made at this season to observe not only
the parts of the trees just named, but to note all other characters
presented by the trees, such as the nature of the trunk and its bark,
the mode of branching, the appearance of the young twigs, and the nature
of the soil and situation in which each species is found.
Our first example is the Barberry (_Berberis vulgaris_)--the only
British representative of its order (_Berberaceæ_)--a smooth, pale-green
shrub, from four to seven feet high, often seen in woods, thickets, and
hedgerows, flowering in May and June. Its branches generally droop at
the tips, and have triple spines at the base of each leaf or cluster of
leaves. The latter are obovate, sharply toothed or even prickly, and
often reduced to a cluster of spines. The flowers are pale yellow, in
hanging racemes. Each has several yellow sepals, the outer of which are
very small; six petals, in two whorls, with nectaries at their bases;
and six stamens. The stamens at first lie on the petals; but they are
very sensitive, and when the filaments are touched by an insect as it
seeks the nectar at their bases, the stamens immediately spring upward,
throwing off their pollen, and often depositing some on the insect's
back. It is thus possible that the cross-pollination of the flowers is
greatly aided by the insect, especially as it will often happen that the
same part of its back which has been touched by the elastic stamen will
come in contact with the stigma of another flower.
[Illustration: THE BARBERRY.]
The Sycamore, also called the Great Maple and the False Plane (_Acer
pseudo-platanus_--order _Aceraceæ_), although not really a British tree,
has probably found a home here for nearly five centuries. It has been
named the False Plane on account of its having been mistaken for, and
called, the Plane, which tree it somewhat resembles in the form of the
leaf, as well as in the character of the smooth, thin bark that peels
off, giving the tree a patchy appearance. It should be noted, however,
that the leaves of the Plane are arranged alternately, while those of
the Sycamore are in opposite pairs; also that the fruits of the former
are in pendulous balls while those of the latter are winged, and
generally in two parts.
[Illustration: THE SPINDLE TREE.]
The Sycamore grows to a height of from forty to fifty feet and flowers
in May or early June, some time after the appearance of the leaves. The
leaves are simple and cut into five lobes, with a palmate venation and
irregularly toothed margins. The flowers are small, yellowish green, and
produced in graceful, pendulous racemes. Each one is about a quarter of
an inch in diameter, with five narrow sepals, five narrower petals,
eight stamens, and a two-lobed, flattened, hairy ovary which develops
into a pair of 'keys' or samaras, with wings about an inch and a half
long.
The Maple (_Acer campestre_) is a much smaller tree, with a very
rugged, corky bark. In woods it often reaches a height of fifteen to
twenty feet, though it produces flowers and fruit long before it is
fully grown; and it is often seen, more or less trimmed and stunted,
among hedgerow shrubs. Its leaves are opposite, two to four inches wide,
on slender stalks, palmately veined, and divided to about the middle
into five obtuse, entire or crenate lobes. The greenish flowers are much
like those of the Sycamore, and appear at the same time, but grow in
loose, erect, axillary racemes; and the wings of the fruit always spread
horizontally in a straight line. On p. 337 is a photograph of a
twig of this tree in fruit.
The Spindle Tree (_Euonymus europæus_), the only British member of the
order _Celastraceæ_, is a moderately common wood and hedgerow shrub
which is usually from four to ten feet high, when untrimmed, bearing
yellowish-green flowers during May and June. Its branches are smooth,
green and angular; and its leaves are opposite, shortly-stalked, oval,
acute, finely toothed, with a shining surface. The flowers are usually
from three to five together in loose axillary clusters. They have a
small, flat calyx of four short sepals; four spreading petals, about a
sixth of an inch long; four stamens, about half the length of the
petals; and an ovary of from three to five cells embedded in the fleshy
disc. The fruits are very pretty, and often form a conspicuous feature
of the hedgerow during late summer. They are lobed capsules which open
at the angles, exposing the bright orange mace that encloses the seeds.
Several of the prettiest of our trees and shrubs belong to the order
_Rosaceæ_, and among these we may name the Dwarf Cherry, Bird Cherry,
Gean, Sloe, Bullace, Hawthorn, Wild Pear, Crab Apple, Service Tree,
White Beam Tree, and Mountain Ash. The first of these, known variously
as the Wild Cherry, Dwarf Cherry, and Red Cherry (_Prunus Cerasus_),
grows from four to eight feet high, and bears white flowers, in almost
sessile umbels, during May and early June. Its bark is of a reddish
colour, and numerous suckers arise from its root. The leaves are
oval-oblong, smooth, firm, and nearly erect; and the fruit is round,
juicy, and red. Although in the wild state the fruit is very acid, this
is the tree from which our sweet, cultivated cherries have been derived.
In order to distinguish this from other similar species, it should be
noted that the tube of the calyx is _not_ contracted at its mouth.
The Bird Cherry (_P. Padus_) is found principally in North England,
where it is moderately common in parts. It is larger than the last,
often reaching a height of fifteen feet. Its leaves are narrow,
somewhat egg-shaped, smooth, with a doubly-serrate margin. The flowers,
which appear in May or June, are white, and arranged in pendulous
racemes; and the fruit is oval, almost black, and bitter.
[Illustration: THE WILD CHERRY.]
Another wild cherry, generally known as the Gean (_P. Avium_), is still
larger, sometimes reaching a height of thirty feet, and is not uncommon
in woods and hedges. The bark is smooth; the leaves abruptly pointed,
soft, drooping, and downy beneath; and the beautiful white flowers are
in almost sessile umbels. The calyx-tube of this species is contracted
at the mouth, and the fruit is either red or black, heart-shaped, and
bitter. The leaves turn to a deep red colour in the autumn.
Among the earliest flowers of Spring are the white blossoms of the Sloe
or Blackthorn (_Prunus spinosa_), which appear in March and April, some
time before the leaves. The shrub grows from four to eight feet high,
has a blackish bark, and numerous branches, the smallest of which
terminate in hard, rigid thorns. The leaves are ovate, finely-toothed,
smooth, stalked, with small, free stipules. The flowers are small,
shortly-stalked, with a free, deciduous calyx of five lobes; five
spreading petals; from fifteen to twenty stamens; and an ovary which
ripens to an almost black, juicy, acrid drupe, about half an inch in
diameter, containing a hard stone, and covered with a bluish bloom. This
shrub is very common in thickets and hedgerows.
The Bullace (_Prunus insititia_), sometimes regarded as a variety of _P.
spinosa_, is a very similar bush, growing in similar situations, and
flowering at the same time; but its bark is brown, and the branches less
spiny. Its leaves, also, are downy beneath; and the flowers, which
appear at the same time as the leaves, are in pairs, on downy stalks.
The fruit is about double the size of that of the last species, either
dark or yellow in colour, less acrid, and drooping.
The above two species are the origins of the damsons and plums of our
fruit gardens.
The May or Hawthorn (_Cratægus Oxyacantha_) is so well known that there
would be no necessity to describe it, were it not for the fact that,
being so familiar, its distinguishing characters are liable to be
overlooked. It is a much-branched shrub, with many of the branches
modified into protective spines. The leaves are simple, smooth,
deeply-lobed and obtuse, have deciduous stipules, and appear before the
flowers. The flowers are generally white, sweetly-scented, and arranged
in corymbs. There are five sepals and five petals, and the numerous
stamens have pink anthers producing brown pollen. The carpels, one to
three in number, are enclosed in the calyx-tube; and the fruit is a
bright red pome with a bony core.
The Wild Pear (_Pyrus communis_) is occasionally met with in woods and
hedgerows, where its white flowers may be seen in April or May. The
leaves of this tree are simple, elliptical, and serrate; and the smaller
branches often terminate in a spine. The flowers are about an inch in
diameter, and arranged in corymbs. They have distinct styles--a feature
which serves to distinguish the blossom from that of the Wild Apple; and
the fruit, which tapers towards the base, is a five-chambered, woody
pome, with a horny core. Two varieties of this species occur, one with
the base of the fruit conical, and the other with the base rounded.
The Crab Apple (_P. Malus_) is very similar in general appearance, but
has no spines; and the flowers, which are in sessile umbels, are white,
with delicate shades of pink. The styles, also, are united below; and
the fruit is globular, yellow or reddish, concave at the insertion of
the stalk, very acid, and five-chambered. This tree is common in
hedgerows as well as in woods, and flowers during May or early June.
[Illustration: THE CRAB APPLE.]
In the woods and hedges of South England we commonly meet with the
Service Tree (_P. torminalis_)--a small tree with downy twigs, and
smooth leaves with from six to ten triangular, serrate lobes. Its
flowers are small, white, and arranged in compound cymes. They bloom in
April and May; and in the autumn their place is occupied by small,
green fruits, spotted with brown, with a two-chambered, brittle core.
The White Beam (_P. aria_) is a small tree, commonly found on the
outskirts of woods on chalky or limestone soils, which might be confused
with the last species. It has large, irregularly-lobed leaves, white and
downy beneath, with serrate edges. The general form of the leaf is
egg-shaped, while that of the Service Tree is cordate. The corymbs of
white flowers bloom in April; and the fruit, though much like that of
_P. torminalis_, is spotted with _red_. There are no less than four
varieties of this tree, distinguished mainly by the forms of the leaves,
the serration of their edges, and the number of lateral veins.
[Illustration: THE MOUNTAIN ASH.]
We have yet another representative of the Rose order in the Mountain
Ash, Rowan, or Fowler's Service Tree (_P. Aucuparia_), which is common
in mountainous woods, and supplies an edible fruit. It is a very
graceful and beautiful tree, with a smooth greyish bark; and pinnate
leaves with from thirteen to seventeen serrate leaflets, downy on the
under side. The flowers are small, of a creamy white colour, in large
corymbs. They bloom in May and June; and later in the year their place
is occupied by the scarlet globular fruits, with a yellow pulp,
enclosing from two to four chambers.
The Black Currant (_Ribes nigrum_), of the order _Grossulariaceæ_, or
sometimes included in the _Saxifragaceæ_, is sometimes found wild in
moist woods, flowering in April or May. It is well known as a garden
shrub, and may be easily recognised by the characteristic odour emitted
from its stems and leaves when bruised. In some northern woods the Red
Currant (_R. rubrum_) is also found wild.
The Wayfaring Tree or Mealy Guelder Rose (_Viburnum Lantana_--order
_Caprifoliaceæ_) is moderately common in the woods and hedges of dry
districts, especially on calcareous soils. It grows from ten to twenty
feet high, and flowers during May and June. Its young shoots are covered
with star-like hairs, which give them a characteristic mealy or downy
appearance. The leaves are simple, elliptical-cordate, serrate, without
stipules, and are downy beneath. The flowers are small, white, perfect,
and arranged in terminal cymes. In late summer the tree is rendered
conspicuous by its _flattened_ berries, which become scarlet as they
ripen and afterwards turn black. A photograph of a twig in fruit is
given on p. 338.
The Ash Tree (_Fraxinus excelsior_--order _Oleaceæ_) is easily
recognised at a distance, either in summer or winter, by the graceful
curves of the lower branches, which droop, and then bend upward at their
extremities; also, on a closer inspection, by the light ashy colour of
the smooth bark of the twigs, and the large, black, triangular, terminal
buds. The leaves are pinnate, with from nine to seventeen
oblong-lanceolate, sessile, serrate leaflets. The flowers appear before
the leaves in April and May, in dense clusters. They have no perianth:
some consist only of an ovary, some only of two dark purple stamens,
while others are perfect flowers with both ovary and stamens. Some trees
have male blossoms only, and therefore produce no fruit; others bear
dense tufts of pendulous, winged fruits which are ripe in October (p.
336), but often remain on the tree till the following spring.
The wing of the fruit is slightly twisted, and thus, when the fruit is
detached, it falls with a slow, spinning motion that allows it to be
carried some distance by the wind, reaching the ground with its seed-end
downwards. The seed does not germinate until the second spring. A
variety of the Ash occurs with simple leaves.
Very early in the Spring--February to April--we may often see the
Spurge Laurel (_Daphne Laureola_) in flower in woods and copses. This is
an erect, smooth shrub, from two to four feet high, with a few erect
branches bearing at their summits crowded clusters of thick, glossy,
narrow, evergreen leaves. Its flowers, of a yellowish green colour, are
in drooping, axillary clusters among the leaves. They have a tubular,
inferior perianth, with four spreading lobes; eight stamens inserted in
the top of the tube; and a free ovary of one cell, containing a single
ovule. The perianth falls early; and the ovary afterwards becomes a
berry-like fruit with a single stone.
[Illustration: THE SPURGE LAUREL.]
Another similar shrub, known as the Mezereon (_Daphne Mezereum_), is
found in similar situations, and flowers at the same time, but it may be
known by its deciduous leaves, and by its pale red flowers arranged in
threes on the side of the stem. These two species are the only British
representatives of the order _Thymelaceæ_.
Two species of Elm are common in our woods and hedgerows. The
small-leaved or Common Elm (_Ulmus campestris_), and the Wych Elm (_U.
montana_). Both are distinguished by their thick, furrowed, corky bark;
and their rough oval-cordate leaves with unequal sides. They are often
placed in the same order (_Urticaceæ_) as the well-known Stinging
Nettles, but some authorities form a distinct order for these two
species alone, under the name of _Ulmaceæ_.
The Common Elm is not indigenous, but was introduced into our country by
the Romans. It is, however, one of our commonest trees, and is
especially abundant in the South. The midrib of the leaf is covered
below with irritating, glandular hairs, somewhat resembling those of
nettles in structure and function; and the stipules are deciduous,
falling early in the season. The flowers are perfect, appearing before
the leaves in March and April, and are in small, dense clusters,
principally on the topmost branches. Each flower has a little,
bell-shaped, persistent perianth; a superior ovary with two styles; and
four or five stamens with black anthers. The fruits are very thin oval
samaras with the seeds above the centre, but they seldom ripen in our
country. They are produced in such abundance that the ground is often
almost completely covered with them when they fall. Botanists recognise
several varieties of this species, but these differ so slightly from one
another that they are barely distinguishable. The Common Elm throws off
a large number of suckers from its roots, often producing a dense
undergrowth round its bole.
[Illustration: THE ELM IN FLOWER.]
The Wych Elm is a native of our country, and is also very common, but it
occurs principally in the woods of the North. It is very similar in
general appearance to the last species, which it also resembles in
having several barely distinguishable varieties; but it generally
attains a much greater girth, and does not throw off such an abundance
of suckers from its roots. Its twigs are downy; and the leaves, which
are larger than those of _U. campestris_, are irregularly doubly
serrate, with hairs on the prominent ribs of the under side, and are
arranged in two straight rows, one on each side of the twig. The flowers
are very similar to those of the Common Elm; and the fruit is a broad
oblong or almost round samara, with the seed in the _centre_. Both
species are pollinated by the wind; and, as is the case with
wind-pollinated flowers generally, the stamens protrude well out of the
flower, and produce abundance of pollen.
[Illustration: THE OAK IN FLOWER.]