Glossary

Apothecium

Reproductive body having an open disc with a layer of asci and sterile structures. The disc of the apothecium may have a distinct margin that is said to be thalline (or lecanorine) if it has algae in its tissue and proper (or lecideine) if it does not.
 

Axil

The angle made where one branch gives rise to another
 

Axis

A major elongate strand of a fruticose lichen.
 

Brown

(of chemical reactions)
 

Bulbate Cilia

Cilia with an onion shaped bulb at the base where they arise from the margin of a lobe.
 

C

Medullary reaction to an aqueous solution of calcium hypopchlorite
 

Capitate

A sub-globular head-like shape.
 

Cartilagenous

Having the structure of cartilage; tough.
 

Cephalodia

structures housing cyanobacteria within a lichen that otherwise has a green algal photobiont.  Cephalodia may be on the thallus surface or embedded within it.
 

Cilia

A coarse hair-like structure growing on the margin or upper surface of lobes or on apothecia.
 

Cortex

A developed layer of compact fungal tissue enclosing other lichen tissues.
 

Crustose

A thallus with the lower surface without a developed cortex, and the lower surface inseparable from the substratum.
 

Cyanobacteria

Blue-green algae: photosynthetic bacteria.
 

Cyphellae

Pores in the lower surface of lichens that are cup-shaped and have a distinct, well developed margin. (cf  pseudocyphellae)
 

Dactyls

Finger-like protrusions on the upper cortex of a lichen that may burst or become sorediate.  Dactyls do not have an abscission layer at their base (cf isidia) 
 

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Erumpent

Bursting at the tip, especially of dactyls and isidia.
 

Foliose

Leafy; a thallus that is flat and thin with pronounced differences between the upper and lower surface, usually more-or-less attached to the substrate along the length of the lobes. (cf  fruticose, crustose)
 

Fruticose

Shrubby; a thallus that has little or no dorsiventral differentiation, lobes or axes with radial symmetry; usually attached only by a holdfast. (cf  foliose, crustose)
 

Holdfast

A tough structure attaching a lichen thallus to its substrate at a single point.
 

Hyphae

Fine strands of fungus
 

Inflated

Swollen, with loosely packed internal hyphae or hollow.
 

Isidia

Tiny cylindrical, coral-like or globular structures on thalli that have a developed cortex-like outer layer; serve as reproductive bodies. Isidia have an abscission layer at their base. (cf dactyls)
 

K

Medullary Reaction to potassium hydroxide (of chemical reactions)
 

KC

Medullary Reaction to potassium hydroxide followed by calcium hypochlorite Medullary Reaction to potassium hydroxide (of chemical reactions)
 

Lobes

Major individual portions of the thallus.
 

Lobules

Small lobe-like structures that may grow on the margin or upper surface of a lobe.
 

Marginal

On the edge of the thallus where upper cortex meets the lower cortex.
 

Medulla

A cottony tissue within a lichen, devoid of algae.
 

Muriform

Of spores - having longitudinal and transverse septa.
 

o

Orange Medullary Reaction to potassium hydroxide (of chemical reactions)
 

P

Medullary reaction to a fresh alcoholic solution of paraphenylene diamine (of chemical reactions)
 

p

Pink (of chemical reactions)
 

Papilla

A small pimple-like swelling on a lobe or axis.
 

Pendulous

Hanging.
 

Photobiont

The photosynthetic organism that provides energy for the lichen. These are either green algae (often Trebouxia or a close relative) or cyanobacteria (commonly Nostoc).
 

Phyllidia

Small lobule-like structures that occur on the lobe margin or upper cortex of some lichens.
 

Pseudocyphellae

Openings through the upper or lower cortex of a lichen, the pores not having a developed margin (cf cyphellae). Pseudocyphellae may be pinprick size, small irregular pores or elongate crack-like structures that penetrate the upper or lower cortex. They are evident on young lobes and should not be confused with cracks that come with age or fine reticulate cracks that sometimes occur as a function of cortical structures.
 

Pustulate

Bursting open, sometimes to produce soredia.
 

Pustules

Small eruption in a surface.
 

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r

Red (of chemical reactions)
 

Rhizines

Well-developed organs of attachment on the lower surface of a foliose lichen. These may be simple (unbranched), irregularly branched, dichotomously branched or terminate in a bushy branching system.
 

Rotund

With a broadly rounded end (cf truncate).
 

Secondary lobes

Small lobes that grow from the centre of an older thallus.
 

Septate

Of spores - having dividing walls.
 

Soralia

Aggregates of soredia to form powdery masses.
 

Soredia

Small clusters of algal cells entangled in fungal hyphae to from granules.
 

Squamule

A scale-like structure.
 

Squamulose

Made of scale-like structures.
 

Striate

Having fine lines, rather like fine scratches.
 

Thallus

A term used loosely here to indicate the main photosynthetic body of the lichen, including podetia (in Cladonia) and pseudopodetia (in Cladia)
 

Tomentum

A layer of hair-like structures other than discrete rhizines.
 

Truncate

The ends (usually of lobes) squared, having the appearance of having been cut of at right angles to the lobe axis (cf rotund).
 

UV

Response of cortex to UV light
 

y

Yellow (of chemical reactions)