224 Glossary
Staminate: An imperfect flower with stamens or pollen-producing structures, but
with no pistil, or seed-producing structure.
Stigma: The pollen-receiving site of the pistil.
Strain: A group of similar individuals within a variety. Advanced generation
random-mating population derived from a few selected inbred lines. A vari-
ety produced by crossing inter-se a number of inbred lines (usually five
to eight) selected for their good general combining ability. The variety is
subsequently maintained by open pollination.
Succulent: A fleshy plant that hold water in itself, usually in the leaves or stem.
Thickened, juicy, fleshy tissues that is more or less soft in texture.
Systemic pesticide: A chemical that is absorbed by a plant and is translocated in its
vessels, either to kill feeding insects on the plant, or to kill the plant itself.
Test cross: Cross made with a homozygous recessive parent to determine whether
an individual is homozygous or heterozygous.
Tetraploid: Polyploidy plant having four sets of identical chromosomes (4n).
Thinning: Removing excess seedlings, to allow sufficient room for growth and
better size and quality in the remaining plants. Removing stems, branches
and fruits to give the plant a more open structure.
Tissue culture: The growing of masses of unorganised cells on agar or in liquid
suspension. Useful for the rapid asexual multiplication of plants.
Top-dressing: A fertiliser or compost applied at the soil level.
Transplant: A seedling that grows its first true leaves, which resemble the adult
plant leaves rather than the seed leaves that first appear.
Transplanting: The process of digging up a plant and moving it to another location.
Unisexual flowers: Flowers having either pistils or anthers, but not both the organs.
Va r ia nt: A variation between strains. A plant that is genetically different from the
wild plant.
Variety: A sub-division of a kind identifiable by growth, yield, plant, fruit, seed or
other characteristics. It also denotes on assemblage of cultivated individuals,
which are distinguished by a character (morphological, cytological, chemical
or others) significant for the purposes of agriculture, or horticulture and
which when reproduced (sexually or asexually) or reconstituted retain their
distinguishing features.
Ver m ic u l it e: The mineral mica, heated to the point of expansion. A good addition
to container potting mixes, vermiculite retains moisture and air within the
soil.
Virus: A deforming microorganism that causes disease and death.
Vitamin A: ß-carotene is a safe non-toxic form of vitamin. It is a powerful anti-
oxidant that helps protect the cells against cancer by neutralising free
radicals, necessary for new cell growth. It counteracts night blindness and
weak eyesight and builds resistance to infections. It slows the progression
of osteoarthritis and cataracts, and helps prevent macular degeneration of
the eyes.
Vitamin B 1 : Thiamin is known as the ‘Morale Vitamin’ because of its beneficial
effects on the nervous system and mental attitude. It enhances circulation,
assists in blood formation, carbohydrate metabolism and digestion. It plays