Characteristics

P. ditristromatica

P. pavonicoides

P. boergesenii

P. fraseri

P. tristromatica

P. pavonica

Vegetative characters

Thallus

Shape

Flabelliform

Semicircular or circular

Flabelliform

Flabelliform

Flabelliform

Semicircular or circular

Calcification on lower/ upper surfaces

Moderate/heavy

No or light/light

Moderate/moderate

Light/heavy

No or light/light

No or light/light

Number of cell layers

Marginal portion (inrolled margin)

2 (2)

3 (2)

3 (2)

3 (2)

3 (2)

3 (2)

Middle portion

A mixture of 2 and 3

3

3

3

3

3

Basal portion

A mixture of 2 and 3

3

3

3

3

3?4

Other characters

Thickness of cell layers

Same thickness at 3-layer portion; and cells of upper layer twice as tall as those of lower layer at 2-layer portion

Same thickness from the margin to middle portion; central cell layer twice as tall as the surface layers at the basal portion

Cells of lower layer taller than those of upper layer; central cell layer shorter than the surface layers

Central cell layer tallest

Central cell layer shorter than the surface layers

Central cell layer tallest at 3 layer portion; same thickness at 4-layer portion

“Vaughaniella” stage

Absent

Absent

Present

Absent

Absent

Absent*

Hair lines

Arrangement of alternating hair lines between both surfaces

Unequal distance

Equal distance

Equal distance

Equal distance

?

Equal distance

Hair lines (lower/ upper surfaces)

Conspicuous/ conspicuous

Moderate/ inconspicuous

Conspicuous/ conspicuous

Conspicuous/ conspicuous

Conspicuous/ inconspicuous

Moderate/ inconspicuous

Structures (lower/ upper surfaces)

Broad-depressed/ narrow-undepressed

Broad-slightly depressed/narrow- undepressed

Narrow- undepressed/ narrow- undepressed

Narrow- undepressed/ narrow- undepressed

?/narrow

Narrow-undepressed/ narrow-undepressed

Reproductive characters

Reproductive system

Dioecious

Dioecious

Dioecious

Dioecious

Dioecious

Monoecious*

Sporangial sori

Position (surface)

Lower

Lower

Lower

Upper

Lower

Lower

Structure

Narrow

Narrow

Narrow

Broad

Narrow

Broad above hair lines, narrow below hair lines