Learn about plant physiology and taxonomy, including general botany, morphology and anatomy. A suitable course for anyone
working with plants, including horticulturalists, agriculturalists,
environmental managers and plant scientists.
Axil The angle between the phyllode and the stem
Bipinnate A compound leaf twice divided (like a fern leaf in general appearance).
Bract A small leaf like structure at the base of the flower stalk.
Calyx The outer ring of the flower (sepals are in this group)
Chlorophyll The green plant pigment in plant chloroplasts.
Chloroplast The organelle in plant cells in which photosynthesis occurs
Corolla The inner ring of the flower (includes the petals).
Decurrent Where the bottom of the phyllode continues down the stem as a raised line, ridge or sheath.
Gland A projection or insertion on the phyllode margin, nerve or stalks.
Glabrous Smooth, without hairs or protrusions
Glaucous Covered with a whitish fur like layer.
Hypocotyl The section of a seedling located between the roots and the place of attachment of the cotyledons
Lamina The leaf blade.
Leaflets The smallest leaf like structures which are part of a bipinnate leaf.
Linear Long, narrow relatively straight sided.
Lobes Partial division of part of a leaf or phyllode.
Meristem A plant part in which cells are actively dividing.
Node Point at which the leaves or phyllodes arise.
Oblique Uneven or off centred, not symmetrical shape.
Oblong Longer than it is broad, but more or less straight sided leaf or phyllode.
Panicle A flowering branch containing several racemes.
Penniveins Feather like veins
Phyllode A leaf with a much reduced or absent lamina, where the petiole and rachis have assumed the functions of the whole leaf.
Pistil The female part of a flower.
Pubescent Soft hairy coating
Pungent Sharp and pointed
Recurved Bent or curved backwards
Reflexed Bent sharply backwards or downwards
Resinous Sticky, having resinous or sap like material.
Scabrous Rough surface
Sessile Without a stalk
Stamen The male part of a flower, consisting of anthers and filaments.
Extract from course notes:
The majority of cultivated plants are flowering plants (or angiosperms).
Angiosperms have four main parts:
- Roots the parts which generally grow below the soil
- Stems the framework
- Leaves required for respiration, transpiration and photosynthesis
- Reproductive Parts flowers and fruits.
The main stem and its branches are the framework that supports the leaves, flowers and fruits. The leaves, and also green stems, manufacture food via the process known as photosynthesis, which is transported to the flowers, fruits and roots. The vascular system within the stem consists of canals, or vessels, which transfer nutrients and water upwards and downwards through the plant (i.e. equivalent to the blood system in animals).
A stem’s growing tip, its apical bud, is involved in the following processes:
• stem elongation,
• organising the arrangement of leaves on the stem,
• laying the foundations for the potential development of branches.
An apical bud includes the following:
• Apical meristem
• Leaf primordia (cellular outgrowths on the sides of the apical meristem that will develop into leaves)
• Axillary bud primordia (bulges at the base of each leaf primordium that will develop into axillary buds, which may in turn develop into branches).
The developing stem divides into short sections, called nodes. Leaf and axillary bud primordia develop here. The stem sections between adjacent nodes are called internodes. As the stem grows, the internodes elongate and space the leaves and axillary buds apart.
To furthermore avoid crowding of leaves, leaf primordia are positioned in different directions from previously produced ones. There may be one or more leaves at each node. The basic leaf arrangements are alternate (in a spiral), opposite and whorled (in a ring).
Stems may be modified for a variety of reasons. Some modifications are:
• Tendrils instead of a defined branch, the stem is modified into a climbing tendril with leaves appearing periodically along the tendril
• Thorns thorns appear along the stem. It is in fact a modified stem, e.g. Bougainvillea.
• Prickle sharp appendage of the epidermis of the stem i.e. it is a trichome. It is not morphologically a stem, leaf, etc. e.g. Rosa spp.
• Stolons or runners above ground e.g. Strawberry (Fragaria vesca).
• Rhizome below ground e.g. Canna spp.
• Stem tubers large fleshy storage regions, e.g. potato. (
• Corm function as a food storage to carry the plant over till next season, e.g. gladioli
• Cladodes and phylloclades a cladode is a branch of a single internode which is flattened to simulate a leaf. A phylloclade is an entire shoot similarly flattened.
Who should study this course?
Anyone studying horticulture and wants a more in depth course offering a deeper understanding of plant science, botany and taxonomy.