A. R. (Arthur Reginald) Horwood.

A new British flora : British wild flowers in their natural haunts (Volume 3) online

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or cut back, shade-plants will survive only in
the hedge bottom and ditch.

The flora of the sward in the first case will
be more akin to that of a woodland, whilst in
the third case the flora will be of a dry-soil
meadow type. The plants in the ditches,
owing to the narrow character of the latter,
will be erect and drawn up, developing spike-
like flowering stems, and reduced or rosette
foliage, whilst the aquatic types will be less
well-developed, and in the intense struggle for
existence will at the lowest level show ab-
normal characters. The hedgerow plants and
trees are largely affected in habit by artificial
trimming or layering.

Flowering Seasons. The flora of the road-
side is decidedly composite, so that the seasons
of flowering of wayside and hedgerow plants



are sufficiently representative. The meadow
types that flourish on the sward are akin to
those that grow in the fields, and these, except
Grasses, are more or less early. Plants such
as the Ragworts, Red Bartsia, and Rushes
are late-flowering. The Sedges usually met
with are early-flowering species, as Carex
verna (or prcecox\, Carex glauca, &c. The
Daisy and the Dandelion are almost perennial.

The ditch vegetation, like that of truly
aquatic formations, is as a whole late, e.g.
Watercress, Great White Stitchwort, many
Rushes, Sedges, &c., whilst Cuckoo Flower is
early in flowering. The plants that lurk in
the hedge bottom are representative of all
months of the year. The Lesser Celandine
appears almost before any other flowers, and
the Spurge Laurel soon after. The Common
Chickweed is nearly perennial. Moschatel is
fairly early, and so, as wayside plants, are
Lords and Ladies and Dog's Mercury, indicat-
ing former woodland. The Red Campion,
also a woodland plant, is a little later. Ground
Ivy is one of the early plants, and Germander
Speedwell also.

In the hedge the Hazel is the first to bloom,
then come the Sloe, Crab Apple, Hawthorn,
and still later the Dog Rose, Cornel, Guelder
Rose, and Buckthorn. Privet is the latest,
save the Ivy. Of the trees, the Elms are very
early, as are the Willows, then the Ash, the
Oak, Beech, Field Maple, and Lime com-
mence to flower by degrees.

Effect upon Height. The continuity or other-
wise of the trees and scrub in the hedgerow
has a marked effect upon the rest of the road-
side flora. Much depends upon the direction
of the road, and the relation of the sun to the
barriers that the hedges form to its path across
the road.

There are roughly four types of vegetation
along a roadside or a hedgerow, and the plants
of each type more or less retain the same rela-
tive standard as to height, save in the case of
the plants on one side which receive least sun,
or are hidden by an overhanging hedge or tree
belt. The height of the ditch plants is regu-
lated by the height of the ditch. Those that
grow vigorously, as Great Hairy Willow-herb,
endeavour to reach above the banks on either
side, and are usually abnormally long. Hence
they must not be taken as typical examples.
The plants at the bottom, as Watercress, are
necessarily dwarfed, and consequent upon the
crowded character of the ditch often lie along
the bottom in a procumbent manner, and so
lose height, even if they do not spread much
more extensively than usual. The plants
below or at the bottom of the hedge, as Three-
nerved Stitchwort, usually lie on the surface,



250



HINTS AND NOTES



but some are elongated to reach the sun.
Those that grow on the hedgebank, such as
Hedge Mustard, are frequently much elon-
gated when on the northern aspect. Others,
as Herb Robert, have a straggly habit, as a
result of their growing forward to the light
through the hedge itself.

Diversity of Types on the Roadside in Relation
to Perennation. The composite character of
the wayside flora renders it variable in respect
of the way in which the plants adapt them-
selves to the growing season, or acquire their
life duration or mode of perennation.

The Elm, Ash, Oak, Lime, Poplar, Willows,
Hazel, Hornbeam, Sycamore, &c., all fre-
quently planted by the wayside, are deciduous
trees. Holly and Yew or Pine are evergreen.
The scrub or shrub type is similarly deciduous
e.g. Hawthorn, Cornel, Spindle, Buckthorn,
Apple, Field Maple, Rose, and the Bramble,
Spurge Laurel, &c., among undershrubs, are
all also deciduous. Box is evergreen, but is
only native on the chalk and oolite at Boxhill
and one or two other places. The aquatic
vegetation is largely herbaceous and perennial.
The sward is made up of herbaceous perennial
or annual Grasses, and some other perennials.
The bulk of the annuals, as Shepherd's Purse,
Wart Cress, &c., are derived from other sources,
cornfields, &c.

Pollination of Roadside Plants. A particular
feature of the roadsides is the wandering of
insects along the roadside. They do not, as a
rule, fly away over the adjoining fields, but
continue their course along the highway.

It is thus not surprising that the bulk of the
wayside plants are adapted to insect visits,
which are numerous, and that most of them
are cross-pollinated. But since nature has
allowed for the exigencies of the weather and
the occurrence of rainy periods, many of these
plants are equally adapted to self-pollination,
as Hedge Garlic, Greater Stitchwort, Perfor-
ate St. John's Wort, Herb Robert, Common
Bramble, Crab Apple, Hedge Parsley, Cornel,
Moschatel, and Elder and Cleavers are self-
pollinated, as a rule. In some the anthers are
mature first, as in the Teasel, Ground Ivy,
and Bugle, in others the stigma, as in the
Sloe, and Hawthorn, and Lords and Ladies.
The Ash, as well as the other hedgerow trees,
and the Nettle are largely pollinated by aid of
the wind.

The Dispersal of Seeds of Roadside Plants.
The linear nature of a roadside, and its
boundary on either side by hedgerows, places
a certain restriction upon wayside plants so
far as the dispersal of seeds is concerned; and
it is therefore, in so far as the agency of the
wind is concerned, more or less definite in



direction, either along the road or from one
side to the other. But it must be remembered
also that the field side of each hedge acts as a
barrier to the dispersal of seeds from the fields,
&c., from a distance, and there may thus be
an aggregation of seeds, stopped by such
barriers, along the highway. Moreover, the
very fact that a road is devoted to traffic, as
has been shown, ensures that seeds will be
dispersed by external artificial agency along
the way. The Clematis, Barren Strawberry,
Hemlock, Hogweed, Teasel, Nipplewort, Ash,
Nettle, have their seeds or fruits dispersed by
the wind. A large number of fruits are edible
or have hooked fruits, and are dispersed by
animals, e.g. Barberry, Sloe, Bramble, Rose,
Crab Apple, Hawthorn, Bryony, Hedge Pars-
ley, Cornel, Moschatel, Cleavers, Spurge
Laurel, Black Bryony, Cuckoo Pint.

In other cases, such as Hedge Garlic,
Hedge Mustard, Greater Stitchwort, St. John's
Wort, Herb Robert, Trailing Vetch, Meadow
Vetchling, Great Bindweed, Red Bartsia, Wood
Basil, Ground Ivy, the plant has a mechanism
of its own for dispersing its seeds.

Soil and the Roadside. The soil of the road-
side is liable to much alteration, not only from
the length and continuity of the road, and the
existence of cuttings which expose new layers,
but also on account of the interlacing character
of the roads. A road taken from S.W. to N.E.
on the east side of Birmingham would largely
pass over the same geological formation and
rock soil.

A road such as the \Vatling Street, or Great
North Road, which cuts across these in a S.E.
to N.W. or S. to N. direction, however, passes
across a number of different formations. In
the west of England the rocks are all older,
and contribute to form siliceous soils. A few
plants need limestone or chalk, as Clematis or
Wood Basil.

A large proportion grow on humus, as Bar-
berry, Greater Stitchwort, Herb Robert, Bry-
ony, Cornel; and some are equally at home on
either sand or clay, as Barbarea, Hedge Garlic,
Spindle Tree, Rose, Hogweed, Hedge Parsley,
Lords and Ladies. Sand without humus is
needed by Hedge Mustard, Trailing Vetch,
Bramble, Barren Strawberry, Hawthorn, Tea-
sel, Nipplewort, Great Bindweed, Nettle.
Clay or sand is the requirement of Barberry,
Crab Apple, Elder, Cleavers, Red Bartsia,
Ground Ivy, Black Bryony; and pure clay is
the soil for Moschatel and Bugle, as well as
the Ash, which grows in a native state best on
limestone. Each plant thus has a special pre-
dilection for some one type of soil.

Methods of Survey. The vegetation of the
roadside is composite. There are zones of



ROADSIDES AND HEDGES



251



vegetation, each of which should be studied
separately.

The margin of the macadam forms one zone,
the greensward forms a second, and answers
to the meadow type of flora. In each case a
percentage of the most dominant plants should
be made. A note should be made as to the
soil characters here, as in the other zones, also
the slope, and relation to the tree zone if it be
well developed. Any unusual features of this
zone, as the occurrence of scrub, of ponds, or
streams that sometimes run parallel with the
macadam should be noted. Where stone-heaps
or gateways with open ground occur these may
be treated as units in themselves.

The intersection of road drains or roadways
at right angles to the macadam should be



noted, and any influences these bring to bear
discriminated.

The next zone, the ditch, is studied as a
small stream or river, where it may show em-
bryonic zonation or bands of vegetation of
different types. When dry it may be con-
sidered as a ground flora to the semi-woodland
type of hedgerow vegetation. Bridges crossing
such ditches should be studied apart, and the
special features recognized.

The hedgerow bank is treated separately,
and the influence of the hedge upon the ground
flora should be carefully studied. The hedge
itself is treated in the same way as scrub, and
plants in the hedge bottom as its ground flora.
Where walls occur they should be studied as
in the section dealing with walls, &c.



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Online LibraryA. R. (Arthur Reginald) HorwoodA new British flora : British wild flowers in their natural haunts (Volume 3) → online text (page 23 of 23)