Cambium: the growing or dividing single layer of cells located between the wood and bark.
Cane: stem of vines and brambles in the dormant stage.
Capsule: fruit derived from an ovary with 2 or more carpels.
Carpel: simple pistil or unit of a combined pistil.
Carpellody: stamens develop abnormally into carpel-like fleshy structures.
Cation exchange capacity: a measure of the soil’s ability to hold such elements as K, Ca, Mg, Na against leaching. High CEC denotes fertile soil.
Catkin: a scaly spike of usually unisexual and reduced flowers.
Cauliflorous: having flowers on the stem or large branches.
Central leader: main dominant stem of a plant.
Chance seedlings: seedlings where parentage is unknown, random or uncontrolled and subject to the variations of sexual reproduction. A number of important fruit varieties have resulted from selection of promising chance seedlings.
Chilling requirement: The growth of flower or vegetative buds in spring, eg with deciduous plants, requires that a certain quantum of cold be experienced. This is often measured in hours experienced by the plant below 7°C.
Chlorophyll: a group of light-absorbing pigments active in photosynthesis.
Chloroplast: the organelle that is the site of photosynthesis in plants (eukaryotic organisms).
Chlorosis: the yellowing of plant leaves characteristic of nutrient deficiency.
Cladode: a stem that functions as a leaf, eg. some cacti.
Cleistogamy: self-pollination prior to flower opening eg hermaphrodite papaya.
Climacteric: marked rise in respiration at the onset of ripening that occurs in all fruits that ripen in response to ethylene.
Clone: group of plants vegetatively propagated from a single mother plant or a mutant.
Complete flower: having all the components: pistils, stamens, petals and sepals.
Cone : mass of ovule-bearing or pollen-bearing bracts or scales arranged spirally on a cylindrical or globose axis.
Coppicing: severe pruning of trees down to the stump and then allowing them to regrow. Not all trees can be coppiced.
Corolla: the second floral whorl of a complete flower, collective term for all free or united petals of a flower.
Corymb: flat-topped inflorescence with outer pedicels longer than inner and flowers opening centripetally; pedicels may be simple or compound.
Cotyledon: the first, rudimentary embryonic leaf of seed plants.
Cross-pollination: pollination by a genetically different plant. An outcross is a cross to an unrelated individual.
Crotch angle:subtending angle between branches or stem.
Cultivar: a cultivated variety, usually given a unique name. Eg. Mangifera indica cv R2E2.
Cuticle: waxy covering on the surface of stems and leaves that acts to prevent desiccation in terrestrial plants.
Cutting: a detached portion of stem or other plant part which, when rooted, produces a whole plant.
Cyme: an irregular umbellate inflorescence in which the primary axis bears a single terminal flower which develops first.
Cytokinins: compounds with many developmental effects on plants, including leaf senescence, nutrient mobilization, apical dominance, formation and activity of shoot apical meristems, floral development, breaking of bud dormancy and seed germination.
Deciduous: detaching or falling off, usually referring to leaves, leaf tips or sepals and petals of flowers after expansion.
Decussate: arranged along the stem in pairs, each pair at right angles to the pair immediately above or below, as in leaves.
Dehiscence: splitting or opening in a regular manner allowing pollen or spores to escape.
Dehiscent dry fruit: mature fruit that has a dry pericarp that opens to let seeds escape.
Denitrification: Process by which soil anaerobic microbes convert nitrate or nitrite to the gases nitrous oxide or nitrogen, subsequently lost to the atmosphere.
Dentate: toothed, having triangular teeth perpendicular to the margin (leaf description).
Dichogamy: Male and female organs mature on the same plant at different times, promoting natural cross-pollination.
Dicotyledon: one of the 2 classes of flowering plants characterised by 2 seed leaves (cotyledons) in the embryo.
Dioecious: species with staminate and pistillate flowers on separate individuals, unisexual.
Diploid: refers to sets of chromosomes; germ cells have one set and are haploid; somatic cells have 2 sets and are diploid (except for polyploid plants).
Dominant: refers to inherited traits; with dominant alleles one copy is sufficient to produce the trait.
Dormant: not active, awaiting stimulus to fulfil a function.
Drupe: a fleshy indehiscent fruit having a hard endocarp and a single seed, sometimes having more than one encased seed.
Drupelet: a diminutive drupe, eg raspberry fruit.
Emasculate: removal of immature staminate flower structures (anthers) to prevent self-pollination.
Embryo: the rudimentary plant in a seed formed after sexual or asexual reproduction.
Endocarp: inner layer of a pericarp.
Endosperm: in angiosperms, an embryonic nutritive tissue formed during double fertilization of a sperm with the polar nuclei, making it triploid.
Epiphyte:a plant that uses another plant for support but does not take nutrients from it.
Epicarp: outer layer of the pericarp or matured ovary.
Epicotyl: portion of the embryo or seedling above the cotyledons.
Epidermis: Outer layer of cells.
Epigeal germination: emergence of cotyledons above the soil.
Epigenetic: heritable changes of gene expression without modification of the DNA sequence.
Ethylene: A gas that functions as a plant hormone. Important effects on plant growth and development including stimulating or inhibiting elongation of stems and roots, enhances fruit development, suppresses flowering on most species, increases abscission of flowers and fruit.