Botanical words and definitions.

Abscission layer Region of cells in a leaf, cutting of the older part of the leaf.

Actinomorphic A flower that is radially symmetrical.

Alternate Leaves or flowers that are on opposite sides of a stem but arranged at alternate intervals.

Annual A plant that dies after a season, perpetuating itself only by means of seed.

Anther The part of a stamen borne on a stalk or filament, that produces the pollen grains containing the male gametes. The pollen-bearing (male) organ of the flower which is supported by a stalk or filament.

Axil The point at which the parts of a branch meet. A more common name might be "joint." There is an axil where the branch meets the stem. Also refered to the angle between the petiole of the leaf and the branch. Vegetative and flowering buds grow from the axils in the Gesneriaceae.

Bract A leaf in whose axil a flower arises or a modified and subsidiary leaf usually growing in the regular leaf axil or in the inflorescence.

Calyx Plural calyxes. The part of the flower that is at the topof the pedicel or stem and to which the corolla is attached. The calyx may be almost entirely tubular or be devided into leafy segments that are called sepals in some families of plants.

Carpel The female organ of the flower consisting of the ovule, style and stigma.

Caulescens Plant with an obvious stem.

Chromosome Thread like structures found in the nucleus of a cell that bear the inherited characters or genes made of DNA.

Chlorophyll The green pigment found in the chloroplasts in the leaves that trap the energy from light to use in photosynthesis.

Clone A group of plants produced by vegetative propagation from a single plant. It is not often pointed out that the parent plant is also part of that clone group.

Corolla A collective term for all the petals of the flower or The petalliferous parts of a flower. The tube and the limb together when the parts are fused. Usually the colorful part of a flower.

Cotyledon The seed leaves in which food is often stored.

Cultivar Any plant which is altered from the species through cultivation. a variation of a species not occuring in nature is a cultivar and so is a hybrid.

Cutting Any section of a plant which is cut off and planted for propagation.

Cytokinins Plant growth substances that bring about cell multiplication.

Diploid A cell containing two sets of chromosomes.

Epiphyte A plant living on the surface of another plant, gaining a positional advantage, but not parasitic upon that plant.

Gamete A sexual reproductive cell.

Habitat The normal environment of a plant in nature.

Haploid Cells containing a single set of chromosomes.

Heterozygous An organism that has different genes controlling a single character.

Homozygous An organism that has a pair of similar genes controlling a single character.

Hybrid The resultant plants of a cross of species or hybrids.

Inflorescence A reproductive shoot bearing a number of flowers.

Lamina The blade of a leaf.

Lip Tube flowers generally have an unequal division of the upper and lower lobes.

Lithophyte A plant growing on the surface of a rock.

Lobe Any projecting segment of a corolla tube.

Meristem The region of cell division in a plant.

Monocarpic Flowerin and fruiting once.

Mutation An inheritable change in a plant due to a change in genes or chromosomes.

Ovary The hollow chamber in which the ovules are borne.

Ovule The structure that will develope into a seed after fertilization.

Peduncle The stalk of a flower.

Petal Sections of the corolla of the flower. It is preferred to use the word "lobe" to describe these in the gesneriads. See lobe

Peloric A flower that is normally zygomorphic becoming actinomorphic.

Petaloid A structure that has become petal like.

Petiole A leaf stalk.

Petiolode A structure below the petiole that bears inflorescences.

Photosynthesis The production of food in grrn plants using the energy of light captured by chlorophyll, carbon dioxide and water.

Phototropism The direction of growth of a plant in response to the direction of the light.

Pistil The whole female organ of the flower, consisting of the ovary, style and stigma.

Radicle The rootlet growing from a seed.

Rosette Usually applied to leaves that form a flat circular pattern close to the ground, sometimes stemless, sometimes developing a stem with age.

Species A group of organisms that are similar and interbreed to produce similar individuals.

Stamen A stalked organ found in a flower, composed of a filament bearing an anther.

Staminode A vestigial stamen.

Stigma The receptive end of the style upon which pollen grains develop to form a pollen tube which grows down the length of the style to reach the ovules witin the ovary.

Style The neck between the ovary and the stigma.

Subgenus A division of a genus where there are clearly marked differences.

Tetraploid Four sets of chromosomes in a cell.

Throat The inside of the tube of the corolla. Sometimes used for the mouth of the tube.

Transpiration The loss of water from the leaves of a plant.

Unifoliate A plant with a single leaf.

Zygomorphic A flower that is bilaterally symmetrical.