Foliage and Their Functions Two

Burdock foliage

 The large foliage of the burdock plant.
The large foliage of the burdock plant. | Source

Notes from a Lancashire Countryman.

In the last article on foliage and their functions I looked at the function of foliage of the trees and plants that they adorn. In this article we shall observe the shape of the foliage including the terms that botanists attribute to these shapes.  The term for studying these shapes is leaf Morphology.

I will once again endeavour to keep the text as simple as possible so that interest is not lost or bogged down in botanical jargon. Even the tips of the leaves have their own botanical terms and it helps in identifying foliage when one has the basic awareness of these terms. Most wild flower books and indeed many books identifying cultivated flowers will use these words when describing the foliage of plants.

Many different words describe the many different shapes of a leaf tip, below is a cross section of these terms. 

Accuminate from Latin accuminare -to sharpen. The tips of this type of leaf are long pointed, tapering into a prolonged narrow tip in a concave amnner.

Acute from Latin acvere -to sharpen  from acus-needle, this type of leaf end in a sharp, but not prolonged tip.

Stitchwort foliage is grass-like

The linear acuminate foliage of greater stitchwort.
The linear acuminate foliage of greater stitchwort. | Source

Cupsidate--from Latin cupsidare -to make pointed from cupus a point. These leaves narrow to a point.

Obtuse from Latin obtusus meaning dulled this type are rounded or blunt.

Truncate from latin truncare meaning to lop, ending abruptly with a flat end, that looks cut off.

Apex toothed.- teeth at the tip. 

Next we consider the botanical terms when describing the base of the leaf. Acumiate and acute see above.

Auriculate from Latin auris an ear the base of these leaves ends with an ear shaped lobed.

Cordate-heart shaped with a notch towards the stalk.

Lesser celandine

THE CORDATE {HEART SHAPED } LEAVES OF THE LESSER CELANDINE.
THE CORDATE {HEART SHAPED } LEAVES OF THE LESSER CELANDINE. | Source

Cuneate- wedge shaped.

hastate from Latin hasta- a spear, shaped like a halbard basal lobes pointing outwards.

reniform from Latin renis, meaning kidney. Kidney shaped but rounder and broader than long.

rotund, rounded leaves.

saggitate--from Latin sagitta an arrow, arrow shaped foliage with acute basal lobes pointing down wards.

truncate-ending abruptly as though cut off.

Let us now review the surface of the leaf. The botanical names to describe the leaf surface include Farinose-bearing very short waxy, whitish powder.

glabrous- from Latin glabra, meaning bald or smooth.

glaucos- from Latin glaucus meaning silvery bluish-green with a whitish bloom,

glutinos-viscid and sticky.

pubescent-covered with erect hairs Especially soft and short ones.

rugose from Latin ruga a wrinkle. leaves are deeply wrinkled.

verrucose-from Latin verruca-a wart leaves covered with a warty prominence.

viscid from latin viscum -mistletoe {or bird lime]-- covered with sticky secretions.

Foliage Texture.

Many species of plants and trees have evolved to have their surfaces covered with hairs which vary greatly in thickness and shape.This covering of hairs on differing species have various functions. Some types hold moisture in to prevent water loss. Others reflect the rays of the sun so as to protect the surface from getting to hot . hairs on many perennials are to protect the surface from frost and ice.

The hairs { Botanist refer to them as trichomes} have many botanical terms alluding to the type of hairs, their texture or appearance. For instance arichnose hairs are very fine, entangled so has to give a cobwebby appearance.

glandular-- with a gland at the tip of the hair.

lanate--with woolly hairs.

Stellate--with star-shaped hairs.

Tomentose ---densely matted with soft white woolly hairs.

The surface of the leaves may be waxy which reduce water loss. Succulent leaves store water and other nutrients. Some have aromatic or toxic qualities to prevent grazing. Some plants have leaves that are adapted-a transformation into tendrils to help them climb. Many members of the Fabiaceae bean family, adopt this strategy. Others adapt a transformation into bracts.

Bracts are modified leaves, especially when associated with a reproductive structure such as a flower. Bracts are often different from the form of true leaves[But not always so} being larger or smaller, or differing in colour or texture to the unmodified leaves of the plant. Some are brightly coloured and thus are there to attract pollinators. 

Bracts that appear in whorls surrounding the stem beneath the flower are collectively known as the involucre.  The daisy family in particular have many species with such bracts are present.

Colt'sfoot

Colt'sfoot have bracts on the stem and an involucre.
Colt'sfoot have bracts on the stem and an involucre. | Source

Leaves that grow in shade tend to be thinner and adorned with less hairs and of a larger size than those on the same plant/tree that are exposed to direct sunlight. The foliage of plants that that tenant dry, hot regions, generally have thicker leaves and of a more leathery texture. many will be adorned with succulent leaves, and, in some cases lack foliage altogether, in this case the stems tend to be densely covered by hairs. Many desert plants have modified leaves in the form of spines.

Plants of the Fabiaceae {pea and bean family ] have modified leaves that turn into tendrils to help them climb and for support.

Bush vetch

BUSH VETCH  HAVE TENDRILS TO AID CLIMBING AND FOR SUPPORT.
BUSH VETCH HAVE TENDRILS TO AID CLIMBING AND FOR SUPPORT. | Source

A Quick Glance at Foliage Shapes.

LINEAR--greater stitchwort--Stellaria holostea.

Lance shaped--ribwort plantain-Plantago lanceolata.

Elliptical--Bog bean Menyanthes trifoliata. 

Oblong--primrose Primula veris.

Spoon shaped--common daisy Bellis perennis.

Kidney shaped, butterbur, Petasites hybridus.

heart shaped-lesser celandine. {see photograph above.}

Three plants with various types of foliage

The lance shaped foliage of the ribwort plantain
The lance shaped foliage of the ribwort plantain | Source
THE TRIFOLIATE FOLIAGE OF BOG BEAN HAS ELLIPTICAL LEAFLETS.
THE TRIFOLIATE FOLIAGE OF BOG BEAN HAS ELLIPTICAL LEAFLETS. | Source
The Trifoliate foliage of the white clover.
The Trifoliate foliage of the white clover. | Source
The oval shaped leaves of the broad leaved willow herb
The oval shaped leaves of the broad leaved willow herb | Source

Arrow shaped--sheep's sorrel, Rumex acetosella.

Trifoliate---Clover, Trifolium species.

Digitate---Crane's-bill species

Palmate lobed, Lady's mantle Alchemilla species.

Pinnate---Meadow sweet, Filipendula ulmaria

PINNATE WITH TENDRIL---Bush vetch , Vicia sepium,

Three various types of foliage

The scalloped margins of Lady's mantle, are palmately lobed.
The scalloped margins of Lady's mantle, are palmately lobed. | Source
THE ARROW SHAPED FOLIAGE OF THE SHEEP'S SORREL.
THE ARROW SHAPED FOLIAGE OF THE SHEEP'S SORREL. | Source
The pinnate foliage of meadow sweet.
The pinnate foliage of meadow sweet. | Source

Bi pinnate--Fens such as the male fern.

3-4 times pinnate -Bracken Pteridium aquilinum

finely toothed-sawwort, Serratula tintoria.

Coarsely toothed,--dog rose Rosa regusa

Alternate, creeping buttercup.Ranunculus repens.

Sheathed. Angelica sylvestris.

Fern fronds

THE FRONDS OF FERNS ARE BI-PINNATE
THE FRONDS OF FERNS ARE BI-PINNATE | Source
THE AIRY FRONDS OF BRACKEN ARE3-4 TIMES PINNATE.
THE AIRY FRONDS OF BRACKEN ARE3-4 TIMES PINNATE. | Source
THE SHEATHED FOLIAGE OF ANGELICA.
THE SHEATHED FOLIAGE OF ANGELICA. | Source

The leaves of ferns are called fronds.

As we have seen leaves are important to plants and trees they are also vital to humans for food such as leaf vegetables and leaf salads, and of course for medicinal purposes. They also have an importance in aesthetic values such as flower arrangements. 

In the next article which will be the fourth in this series of how plants live and thrive we move on to the flower and its components.

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Comments 4 comments

D.A.L. profile image

D.A.L. 5 years ago from Lancashire north west England Author

Hi thoughforce, your feed back is encouraging. It is { I find} quite difficult to explain things in lay- mans' terms that keep the reader interested without getting over powered with botanical terms. You may be interested in the hub Those Complicated Latin names explained. Thank you for reading and taking the time to comment it is appreciated. Best wishes to you.


thougtforce profile image

thougtforce 5 years ago from Sweden

This is such a great hub! I have only learned a few latin words, and have just beginning to understand the point of learning them. It is great to understand the plants characteristics from the name. And now I have learned some more!You have succeeded to explain this in an easy way and also shown the plants amazing ability to be just right for their livelihood! I will bookmark this hub, for future reading! Thanks!


D.A.L. profile image

D.A.L. 5 years ago from Lancashire north west England Author

Darski, once again I must thank you for your encouraging comments my friend, you are a true friend. Best wishes to you.


Darlene Sabella profile image

Darlene Sabella 5 years ago from Hello, my name is Toast and Jam, I live in the forest with my dog named Sam ...

Oh I just love this hub, it is excellent, I would love to learn what plants are dangerous to our house pets, they seem to want to eat the weeds outside in the summer and it scares me. This hub is one of many, I sometime have to re-read them in order to grasp the terms, I really love learning about them, this is so fascinating. I rate up up up your fan and friend forever, darski

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