Table 3 Comparisons of vegetative and sporangial structures among the species of Exallosorus , Homoeostrichus and Zonaria

Thallus thickness

88–100 μm

150–200 μm

105–180 μm

120–170 μm

90–115 μm

66–300 μm

No. of cell layers

2–4

6–7

4–7

6

4–6

Cortical /Medullary cells

1

1(2)

1(2)

1(2)

1(2)

2(1)

Sporangia

Tetra-, Single

unknown

Tetra-, Sorus

Tetra-, Sorus

Tetra-, Sorus

Octo-, Sorus

Indusium

-

x

-

+

+

+

Paraphyses

-

x

Brown, in sorus

-

Brown, near sorus

Whitish, in sorus

Stalk cell

1

x

Multicellular

1

1

-

Oogonia

unknown

unknown

Sorus

unknown

Sorus

Sorus

Indusium

x

x

-

x

+

+

Paraphyses

x

x

Brown, among oogonia

x

Brown, near sorus

-

Stalk cell

x

x

-

x

1

1

Antheridial sorus

unknown

unknown

sorus

unknown

sorus

sorus

Sorus border

x

x

Brown paraphyses and sterile filaments

x

Cortical cells

Slightly elongate sterile cells

Stalk cell

x

x

1

x

1

1

References

f

b

b, c, d, e

a, e

b, d, e

b, c, d, e