Glossary

Aerobic:  presence of oxygen

Akinete: cell used for the vegetative reproduction in blue algae when conditions are favorable, resisting to the unfavorable conditions by thickening the cell walls after accumulation of food reserve.

Anaerobic:  absence of oxygen

Androsporanges: in general they are sporanges producing male spores.

Androspore: spore formed in the androsporange (male spore)

Antheridium: male reproductive organ producing antherozoids or male gametes

¶Apothecium:¶  ascogenous or open ascocarp ( in Ascomycetes),

Archegonium: female reproductive organ producing oosphere or female gametes

Cambium: embryonic tissue of roots and stems whose cells undergo periclinal divisions in both directions thus producing layers of cells laid out in the radial direction.  It can be the vascular cambium or the phellogen.

¶Carpogonium:¶ female gametocyst formed of a cell supporting a trichogyne

Casparian strip (or band):  waxy layer organised on the four faces of the endodermal root cells and which forces water and the aqueous solutions to cross them rather than to circulate between them.

Chlorosis:  yellowing of the sheets of a plant following the loss of       chlorophyll

¶Cingulum:¶ transverse hollow (in Dinophyceae) in which one of the two flagella are inserted.

Cladode: very flattened short stem, deprived of terminal bud and leaves.                                                                                                                           

¶Cladome:¶ group of filaments with final or subterminal growth

¶Cleistothecium:¶ closed ascocarp¶

Coccospore: ¶asexual reproduction spore surrounded by a thick wall to resist to the dessication; it is a dissemination spore in some blue algae

Collateral bundle: bundle having the phloem only on one side of the xylem.  A bicollateral bundle has an internal and external phloem laid out on both sides of the xylem. 

Collenchyma : supportive tissue made up of more or less elongated live cells and with thick but not lignified cellulose walls, frequent in the parts of the stems and leaves undergoing primary growth. 

¶Columella: ¶sterile tissue located in the centre of the capsule (mosses)

Companion cells: parenchymatous cells in the phloem of angiosperms associated with sifted cells with which they have the same origin. 

Cone: male or female inflorescence of Gymnosperms made of an axis around which ovuliferous or sporangiferous scales are arranged

Conidia: dissemination spores in fungi.

Conidiophore: mycelial filament bearing conidia

Cork or suber : protective tissue composed of dead cells with suberised walls, which are made by phellogen.  It replaces epidermis in old stems and roots. 

¶Cormophyte: ¶ plants having aerial axis including Bryophytes, Pteridophytes and Spermatophytes

Cortex: tissue located between the epidermis and conducting tissues (central cylinder) on the roots and stems level. 

¶Cryptogams: ¶plants with hidden reproductive organs. They are non flowering plants 

Dioecious ¶: male and female flowers are beared by ¶different plant individuals 

¶Elaters: ¶dead cells with thickened wall which helps in opening the capsule for spores dispersal (bryophytes)

¶Embryophyte: ¶Cormophyte

Endoderm :  tissue made up of only a single layer of cells and which circumscribes the central cylinder of a root. 

¶Endoprothally: ¶development of the prothallus inside the spore (pteridophytes)

¶Endothecium: ¶central cell layer of the capsule in mosses producing the columella (central sterile column) and the sporogeneous tissue¶

Epiphyte:  a plant which grows on a plant-host without becoming a parasite

Eusporangiate: ¶ a group of ferns whose spores are produced in a sporangium protected by several cell layers 

Fibre: sclerenchyma cells elongated with streamlined ends and generally lignified walls and a reduced lumen.

¶Gametophyte: ¶haploid individual (with n chromosomes) producing gametes

¶Gonophore: ¶branch carrying carpogone in algae

Guttation: water droplets emission at the end and on the edges of a leaf.

Gynosporophyll: megasporophylls or bracts bearing megasporanges on their axils

¶Heterocyst: big¶ cell used in asexual reproduction (Cyanophyceae)

¶Heterosporous: ¶plantccccc cc    producing different types of spores: microspores (producing male prothallus) and macrospores (producing female prothalli)

Heterotrichous: ¶case of algal thallus with two categories of filaments, some creeping on the substratum and others erect and perpendicular to the creeping ones 

Homosporous: ¶producing one type of ssporsep    plant producing identical spores (one type of spores) 

¶Hormospore: group ¶ of cells which encyst and transform into spores (Cyanophyceae)

Hypotonic:  of inferior osmotic pressure

Isotonic:  of the same osmotic pressure

Laticifer : cell or sequence of cells containing a characteristic substance called latex. 

Lenticellate: which is in connection with the lenticels

Lenticels: opening in epidermis or bark of a young stem by which air can penetrate. 

¶HomosporousH ¶Leptosporangiate: refers to¶ a group of ferns whose spores are produced in a sporangium protected by one cell layer 

Lumen (of a cell): space delimited by cellular wall. 

Macro-element:  essential element in high concentration

Macrosporangia or megasporangia:  sporangia in which megaspores (or haploid spore cells) produce the female gametophyte in heterosporous plants. 

¶Mastigosome:¶    cavity where flagella are inserted, also called blepharoplast

Megasporange: female sporange producing megaspores which germinate into female prothalli

Megaspore: female spore

Megasporophyll: bract bearing megasporanges in its axil

¶Meiospores: young  ¶spores grouped into tetrad

Meristem : embryonic tissue made up of undifferentiated cells and which constitutes certain zones of growth in plants. 

Mesophyll: foliar tissue made up of parenchymatous cells located between the two epidermises. 

Metaxylem, metaphloem : part of xylem, primary phloem which differentiates after the protoxylem and protophloem but before the xylem, secondary phloem. 

Micro-element: essential element in low concentration

Microglia:  neuroglial cell of mesodermal origin that can become phagocytotic.

Micropyle¶: interruption of the ovule integument which allows the male gametes to penetrate in the ovule

Microsporange: male sporange producing microspores which germinate into male prothalli

Microsporangia : sporangia in which microspores (or mononuclear (?) grains of pollen i.e haploid spores) produce the male gametophyte in heterosporous plants). 

Microspore: male spore

Microsporophyll: bract bearing microsporanges in its axil

Moniliforme: in the form of grains

Monoecious: ¶plants having male and female flowers on the same individual 

¶Monostromatic: flattened ¶thallus forming a pseudoparenchyma with a single layer of cells

¶Nannospore: ¶unicellular and small reproduction spore (blue algae) without cell wall

Nucellus: central tissue of the ovule or macrosporange

¶Oocyst: ¶oogonium or organ in which the oospheres are produced

Ostiole : opening in the leaves and stems epidermis surrounded by two stomatic cells and used in the gaseous exchange. 

Parenchyma : plant tissue less differentiated, found in cortex and pith of stems, in cortex of roots and between the two epidermis of the leaf. 

Pentamerous: parts of the flower which are a multiple of 5 (5,10,15,…)

Pericycle :  part of stele parenchyma extended between endoderm and phloem, present in roots

Periderm : set constituted by suberophellodermic zone and its tissues (suber and phelloderm). 

Perisperm :  a reserve tissue in seeds comparable with the endosperm but coming from the nucellus. 

¶Peristome: a membrane made of ¶32 teeth arranged in two rows situated in the operculum in mosses for the protection of the capsule

¶Perithecium: ¶ascocarp opened at maturity by an ostiole or even closed  ¶

Phelloderm : tissue resembling cortical parenchyma produced by phellogen in a centripetal way in certain stems and roots.

Phloem:  plant conducting tissue which channels organic substances. 

Phosphorylation:  synthesis of ATP

Photolysis:  reaction of bonding separation

Photophosphorylation: transformation of the luminous energy absorbed by the chlorophyll pigments in the form of energy directly usable by the cell metabolism

¶Phycocyanine: blue-green ¶pigment

¶Phycoerythrine: ¶red pigment

¶Planocoque: ¶coccospores without flagella moving by sliding or snaking

¶Planogametes: motile¶ gametes with flagella

Plasmolysis: when the medium has a pressure of suction superior to that of the plant, the cell loses water and reaches minimum volume: this fact is known as plasmolysis.

Pluristromatic: flattened  ¶thallus forming a pseudoparenchyma with several layers of cells

Pollen tube: tube formed after the germination of  the pollen grain, containing the vegetative and reproductice nuclei (male prothallus)

Procambium : primary meristem or meristematic tissue, which differentiates in primary conducting tissues. 

Prothallian tube: tube formed by the germination of the the female cell in Welwitschia which fertilises the male nucleus¶

Prothallus: organ¶ developing from the germination of spores in pteridophytes and spermatophytes

Protoderm : primary meristem or meristematic tissue which gives rise to the epidermis. 

¶Protonema: ¶pluricellular filament developping from the germination of spores in mosses

Protoxylem, protophloem : first elements of the xylem and primary phloem which appear in a plant body. 

Punctuation :  small cavity in the cellular wall where primary wall is not covered by a secondary one and where communication between xylem conducting elements can take place. 

¶Pycnidium: flash- like fruiting body ¶containing conidia called pycnidiospores

Sclerenchyma : supportive tissue in higher plants made up of generally dead cells and  having  thick and  rigid walls. 

Sclerites : sclerenchyma cells of variable form which an not very elongated and having thick secondary walls. 

¶Spermatium: inert male ¶gamete

¶Spermatocyst: organ ¶producing sperms

¶Sporocyst: organ ¶producing spores

¶Sporophyte: individual diploid (¶with 2n chromosomes) producing spores

Stele: central cylinder of the stem or root or plant conducting system with associated tissues (pericycle, intrafascicular zones and pith).

Stomata: structure belonging to the leaves epidermis and made up of two guard cells (stomatic cells) laid out around the ostiole; the stoma controls the rate of the gaseous exchange. 

Suberin : fatty substance that is present in the cellulose wall of the cork cells and in the endoderm band of Caspary.

Tetramerous: parts of the flower are a multiple of 4 (4, 8, 16,…)

thrombin

Tillering: when a plant grows stems on the same tuft or the same foot.

Trachea or perfect vessels: xylem conducting elements made of dead and hollow cells, with rigid walls whose ends disappeared to allow an easy circulation of crude sap.

Tracheid : imperfect vessels of xylem made up of dead and hollow cells, and with rigid walls whose porous ends let the sap circulate. 

Trimerous: parts of the flower are a multiple of 3 (3, 6, 9,…)

Turgescence:  maximum volume reached by a cell when the osmotic pressure and the membrane pressure are equal.

Xerophyte:  plant adapted to dryness

Xylem: conducting tissue of crude sap towards photosynthetic tissues of the plant.