Glossary

acrocarpous   used to describe an erect habit in mosses 

alternation of generations      term referring to a life cycle in which there is more than one free-living stage, typically a spore-producing sporophyte and a gamete-producing gametophyte 

anisogametes    motile gametes which differ slightly in size 

autotrophic nutrition  synthesis of organic food molecules from inorganic compounds such  as carbon dioxide  

asexual reproduction production of new individuals from cells of a single parent

benthic  attached to the substratum and submerged 

bisexual   having both male and female sex organs

circinnate vernation  the coiled arrangement of young leaves of ferns & cycads

clade a monophyletic lineage of organisms sharing a common ancestor

coenobium (pl. coenobia)   a colony of a fixed number of cells  

coenocytic     multinucleate, formed by nuclear divion without cross wall formation  

cryptogam    an old term for a non-seed plant; cryptogam means hidden wedding, i.e. as they produced no seeds their sex lives were unknown for a long time  

diatoms unicellular, photosynthetic microalgae with walls of silica

dinoflagellates unicellular algae usually with two flagella and with armoured plates. They may be autotrophic or heterotrophic or a mix of these.

dioecious    used to describe plant species in which male and female sex organs are borne on separate individuals

diploid having two sets of chromosomes

embryophyte a plant which retains the fertilised egg or zygote within the female sex organ where it develops with protection into an embryo

endospory   a condition in which the gametophyte develops within the spore wall, rather than externally 

endosymbiosis a mutually beneficial relationship where one organism lives inside another

epiphyte    a plant that grows on another plant. No parasitism is involved. The epiphyte must be rooted on the surface of the host. Vines rooted in the soil and climbing up on another plant are not epiphytes. 

eukaryote    organism the cells of which have a defined nucleus and internal membranes

flagellum/a    whip-like extension of the cytoplasm for propelling the cell

floridean starch    an algal reserve resembling glycogen or amylopectin 

free nuclear division    mitotic division of nuclei without accompanying cytokinesis, i.e. nuclei divide in a common cytoplasm, the cells walls only forming around each later 

gametes reproductive cells that fuse to form a zygote

gametophyte gamete-producing plant in the life cycle

haploid having one set of chromosomes

heterospory    a condition in which an organism produces two different types and sizes of spores, viz. microspores and megaspores 

heterotrichous (filament)    a growth pattern of algae with prostrate filaments for attachment and erect, spreading filaments for photosynthesis  

heterotrophic nutrition a mode of nutrition where the organism relies on other organisms for food

holdfast    algal organ for attachment  

homospory   a condition in which an organism produces only one type  and size of spore, viz. microspores

hygroscopic movement     movement by the gain or loss of water  

irregular symmetry    irregular flowers are bilaterally symmetrical; they are divisible into equal halves about 1 plane only

laminarin    a ß1,3 glucan reserve  

meristem a region of actively dividing cells

monoecious     used to describe a species in which a single plant carries both male and female sex organs 

multicellular composed of more than one cell

multiflagellate having many flagella

oogamy    reproduction in which the female gamete is large and non-motile and the male gamete small and motile

paramylon    a ß1,3 glucan reserve  

perianth    a collective term for the sepals and petals of the flower, especially when these are indistinguisable 

Phanerogam     a seed plant – gymnosperm or angiosperm.The term literally means “open wedding” and refers to the fact that reproduction in these plants was clearly understood unlike the case in lower plants (Cryptogams) in which it was for a long time something of a mystery

phycobilin – class of pigment found only in algae, comprising red phycoerythrin and blue-green phycocyanin  

planktonic – free-floating  

pleurocarpous – prostrate (used for mosses)  

prokaryote    simple organism without a defined nucleus or internal membranes  

protonema (pl. protonemata) the filamentous (moss) or thallose (fern) gametophyte stage of non-seed plants  

protoplast cell contents within the cell wall, viz. the vacuole and surrounding cytoplasm

pyrenoid     proteinaceous region of chloroplast, sometimes the site of accumulation of carbohydrate reserve

regular symmetry  regular flowers have radial symmetry; they are divisible into equal halves in 2 or more planes 

rhizoid     hair-like, filamentous anchorage/absorbing organ  

ribosome        organelle responsible for protein synthesis 

seed fern    extinct seed-bearing plants with fern-like leaves 

sorus (pl. sori)            cluster of sporangia of a fern  

sporophyll     a spore-bearing leaf  

sporophyte spore-producing stage of the plant

stele            vascular tissue (the xylem and phloem together) 

superior     ovary is exposed in the flower – above the point of attachment of the perianth and anthers 

strobilus     a cone-shaped cluster of spore-bearing leaves 

syngamy fusion of gametes in sexual reproduction

thallus    term given to the body of a lower plant which has no recognisable shoot, root, leaf regions 

thallophyte    an organism not differentiated into shoot and root, the cells of which have a cell wall; originally used for bacteria, fungi and algae

unicell(ular) composed of a single cell

unisexual   having either male or female sex organs but not both 

zoospores motile spores

zygote cell resulting from the fusion of two gametes