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APPENDIX 6 Glossary

The authors have kept the use of technical terms within reasonable bounds so as to make it possible for the reader to consult the handbook without constant reference to the glossary. The majority of words included are botanical terms frequently used in taxonomic literature. The explantations of the terms have been derived principally from the following sources (1) Cavanagh (1981), (2) McCusker (1981), (3) Fowler and Fowler (1951), (4) Boland et al. (1981) and (5) Gunn (1981). The main reference consulted for each term is indicated after each explanation.

AREOLE (of seed) The area encompassed by the pleurogram. The differences between the areole and the remainder of the face may be slight differences in colour, surface texture or fracture lines. (1).

ARIL (of seed appendages) A pulpy structure which grows from some part of the ovule or funicle after fertilization and invests part or the whole of the seed. (5).

BIPINNATE (of compound leaves) Twice pinnately divided; twice compound. (2).

BISEXUAL (of flowers) Bearing both male and female organs together. (2).

BRACT A leaf-like structure, different in form from the foliage leaves and without an axillary bud, associated with an inflorescence or flower. (2).

BRACTEOLE A small bract-like structure borne singly or in pairs on the pedicel or calyx of a flower. (2).

CALYX (of flower) The sepals of one flower collectively. (2).

CHROMOSOME A thread-like structure in the nucleus of a cell, containing a linear sequence of genes. (2).

COMPOUND (of a leaf) Having the blade divided into two or more distinct leaflets. (2).

CUTICLE A waxy, structureless and water-permeable layer deposited over the whole of the surface of the seed except the hilum. (1).

DECIDUOUS Shed periodically or normally. (3).

DEHISCENT (of fruit) Breaking open at maturity to release the contents. (2).

DORMANCY (of seed) A resting or quiescent condition. In acacias dormancy is frequently imposed on a non-dormant embryo by the ‘hard’ seed coat which prevents water from reaching the embryo. (4).

ENDOSPERM (of seed) The nutritive or food storage tissue present in the seeds of some species. (1).

EVERGREEN Bearing green leaves throughout the year. (2).

FAMILY (botanical) A group of allied genera. (2).

FUNICLE = funiculus (of seed appendages) The ‘umbilical cord’ of the seed, attaching it to the pod. When detached from a mature seed near the seedcoat it leaves a scar (the hilum). (1).

HARD SEEDS Seeds with thick and tough testas which delay water penetration and germination.

HEAD (inflorescence) A compound inflorescence where the individual flowers are closely crowded together to form a bell-like structure.

HILUM (of seed) The scar left by the abscission of the funicle upon maturation of the seed. It is adjacent to the tip of the radicle. (1), (5).

INDEHISCENT (of fruit) Not opening at maturity. (2).

INFLORESCENCE The group or arrangement in which flowers are borne on a plant. (2).

LEGUME A fruit formed from one carpel and either dehiscent along both sides or indehiscent. (2).

LENS (of seed) A dome shaped, raised area of the seed coat, situated close to the hilum on the side opposite the micropyle. It is the area where water initially penetrates the otherwise impermeable testa. Sometimes referred to as a strophiole. (1), (5).

MICROPYLE (of seed) In mature seeds, a plugged opening, although formerly it was a passage in the ovule stage between the integuments for the pollen tube. (1), (5).

MONILIFORM Like a string of beads. (3).

MORPHOLOGY Study of the form of plants. (3).

OVARY The basal portion of a carpel or group of fused carpels, enclosing the ovule(s). (2).

OVULE A structure in a seed plant within which one or more megaspores are formed and which develop into a seed after fertilization. (2).

PALISADE LAYER A layer of elongated cells, more or less hexagonal in transection and usually thick walled, in the testa. The cells are referred to as Malpighian cells and these constitute the main barrier to water penetration in the seed. (1).

PEDICEL The stalk of a flower (or fruit). (2).

PEDUNCLE The stalk of an inflorescence

PETAL (of flowers) A member of the inner whorl of non-fertile parts surrounding the fertile organs of a flower, usually soft and coloured conspicuously. (2).

PETIOLE The stalk of a leaf. (2).

PHENOLOGY Study of the times of recurring natural phenomena, especially in relation to climatic conditions. (3).

PHYLLODE A leaf whose blade is much reduced or absent, and whose whole petiole and rhachis have assumed the functions of the whole leaf. (2).

PINNA A primary segment of the blade of a compound leaf. (2).

PINNATE (of compound leaves) Divided into pinnae; once compound. (2).

PLEUROGRAM (of seed) A fine groove in the testa on each side of the seed. Forms the boundary of the areole. (1).

POD See LEGUME.

POLLEN The male elements of flowers. Produced in the anthers.

PROVENANCE The original geographic source of seed or propagules. (4).

RHACHIS = rachis The axis of an inflorescence or pinnate leaf. (2).

SEED The dispersal or germination unit of a fertilised ovule. (5).

SEPAL (of flowers) A member of the (usually green) outer whorl of non-fertile parts surrounding the fertile organs of a flower. (2).

SESSILE Without a stalk. (2).

SPIKE An unbranched, indeterminate inflorescence in which the flowers are without stalks adj. spicate. In acacias it refers to the inflorescences being in cylindrical clusters. (2).

SPINE A stiff, sharp pointed structure, formed by modification of a plant organ. A spine has a vascular supply continuous with that of the stem whereas a prickle is merely an epidermal outgrowth without a vascular supply. (2).

SPINESCENT Ending in a spine; modified to form a spine. (2).

STAMEN One of the male organs of a flower, consisting typically of a stalk (filament) and a pollen-bearing portion (anther). adj. staminate. (2).

STAMINATE See STAMEN.

STIPULE One of a pair of appendages at the bases of leaves in many dicotyledons. In some species e.g. in some acacias these are modified into spines. (2).

STROPHIOLE See LENS.

STYLE An elongated part of a carpel, or group of fused carpels, between the ovary and the stigma. (2).

TANNIN An astringent substence, available naturally in the bark (and sometimes the wood) of different species of trees (especially Acacia and mangrove species), used in converting hide to leather.

TESTA The seed coat; in most leguminous seeds the testa consists of four layers - a cuticle, Malpighian cells, osteosclereid cells, mesophyll cells; endosperm may or may not be present. (1).

VENATION (of leaves) The arrangement of veins in a leaf. (2).

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