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 |