Basal filaments:

unistratose layer of filaments running more or less parallel to the substratum; in dimerous plants.

Branching:

arrangement of the main and secondary axes.

Cell connection:

linkage between contiguous cells or contiguous cell filaments, may be distinguished in primary, secondary pit-connections and cell fusions.

Cellular filament:

a branched or unbranched row of cells joined end to end by primary pit-connections.

Coaxial:

a type of anatomical organization in which cells of contiguous core filaments in monomerous portions of a thallus are laterally aligned in curving rows (Woelkerling, 1998).

Conceptacle:

an enclosed chamber opening outwards, which contains reproductive structures. They can be distinguished in sporangial and gametangial conceptacles.

Cortex:

collective terms for filaments occurring externally to the medulla and running more or less at right angles to the thallus surface; in monomerous plants.

Dimerous:

a type of thallus construction which consists of unilayered basal filaments ("hypothallium" of older literature), from which the erect filaments ("perithallium" of older literature) arise dorsally at right angles.

Epithallial cell:

a cell formed outwardly from either a basal cell or a subepithallial initial. Epithallial cells are present at the surface of most coralline thalli.

Erect filaments:

filaments at more or less right angles to basal filaments; in dimerous plants.

Excrescence:

term used for thallus outgrowths such as lamellae, protuberances, etc. with different shapes.

Geniculum:

uncalcified segments between calcified intergenicula in articulated coralline algae.

Germination disc:

pattern of cells which represent the first developmental phase of algae; within the Corallinales it represents the first stage of the growth of the basal disc necessary to the attachment to the substratum.

Intergenicula:

multicellular calcified segment between uncalcified joints (genicula) in articulated coralline algae.

Maërl:

a term used for branched loose-lying, non-geniculate coralline algae. The accumulation of living or dead algae may form a deposit called maërl bed (or rhodolith bed).

Margin:

peripheral area of a dorsiventral, non-geniculate thallus.

Medulla:

collective term for filaments occurring internally to the cortex and running more or less parallel to the thallus surface usually composed of packed colourless *filaments; in monomerous thalli.

Monomerous:

a type of thallus construction which consists of basal multilayered core filaments ("hypothallium" of older literature) which can be coaxial or non-coaxial. Some derivates of core filaments curve outward and collectively form a more peripheral region ("perithallium" of older literature). Michael Rasser   http://www.paleoweb.net/algae/algae/thallus_organ.htm

Multiporate:

a therm used to describe a tetrasporangial/bisporangial conceptacle in which the roof is perforated by a number of pores through which spores are released. (Woelkerling 1988)

Non Coaxial

basal multilayered core filaments ("hypothallium" of older literature) which can be non-coaxial (= plumose). Some derivates of core filaments curve outward to form the peripheral filaments ("perithallium" of older literature). Michael Rasser http://www.paleoweb.net/algae/algae/thallus_organ.htm

Pore:

hole in a conceptacle roof through which spores escape. It may be single (uniporate conceptacles) or multiple (multiporate conceptacles).

Reproductive cells:

cells aimed to the process by which new individuals are formed and by which the species is perpetuated.

Rhodolith:

a term sometimes used for more or less nodular form of unattached non geniculate coralline algae developed around a nucleus (e.g. a small stone, a shell fragment or sand grains) and which usually consist of a number of concentric thallus layers.

Sorus:

term for a structure or a locus composed of a group of cluster of reproductive organs such sporangia.

Thallus:

a term used to define the plant body in which there is no organization into tissues (not differentiated into vascularized roots, stems and leaves etc.).

Tip:

distal portion of the intergeniculum in articulated coralline algae.

Trichocyte:

a complex of one or more surface or near surface cells interspersed with normal vegetative cells from which hair grows. They can be single, grouped (trichocyte field), intercalary or in terminal position. In geniculate species they can be distinguished in type A, type C, type J .

Uniporate:

a term used to describe a conceptacle in which the roof is perforated by a single pore through which spores or gametes pass. (Woelkerling 1988)