Mastophoroideae

(Setchell 1943: 134 - as ‘Mastophoreae’) Thallus non-geniculate; some but not all cells of contiguous vegetative filaments normally joined by cell fusions; secondary pit connections apparently absent or comparatively rare; tetrasporangia/ bisporangia lacking apical plugs and borne within uniporate conceptacles.

Hydrolithon Foslie 1909: 55

• Thallus non-geniculate, non-endophytic, and lacking haustoria;
• thallus lacking a basal layer of palisade cells throughout;
• tetrasporangial conceptacles uniporate;
• pore canals of tetrasporangial conceptacles lined by a ring of conspicuous, elongate cells that arise from filaments interspersed among sporangial initials;
• these cells do not protrude into the pore canal, and are oriented more-or-less perpendicularly to the roof surface;
• male conceptacles containing simple spermatangial systems that are restricted to the conceptacle floor;
• gonimoblast filaments borne from the margin of the fusion cell.

COMMENT: Species formerly placed in Fosliella are now included in Hydrolithon. ETYMOLOGY: From hydro (water) and lithon (stone).
ETYMOLOGY:From hydro (water) and lithon (stone).
KEY FEATURES:Hydrolithon is best characterised by the pore canals of tetrasporangial conceptacles being lined by a ring of conspicuous, elongate cells that arise from filaments interspersed among sporangial initials. These cells do not protrude into the pore canal, and are oriented more-or-less perpendicularly to the roof surface. Thin, Fosliella-state species are recognised by the 4-celled germination disc, as opposed to an 8-celled germination disc in Pneophyllum.

Lesueuria Woelkerling & Ducker 1987: 193

• Thallus non-geniculate, endophytic, and posessing haustoria;
• vegetative system consisting only of filaments within the host thallus;
• epithallial cells lacking on vegetative filaments;
• tetrasporangial conceptacles apparent externally on the host thallus;

COMMENT:Lesueuria is the only known mastophoroid genus in which the vegetative thallus is endophytic and in which haustoria occur. It is only known to occur in Metagoniolithon.
ETYMOLOGY:Lesueuria, after C.A. Lesueur (1778-1846), French naturalist and illustrator who was among the first to collect coralline algae in Australia.
KEY FEATURES: Lesueuria is the only known genus of Mastophoroideae in which the vegetative thallus is endophytic, and in which haustoria occur.

Lithoporella (Foslie) Foslie 1909: 58

• Thallus non-geniculate, non-endophytic, and lacking haustoria;
• thallus possessing a basal layer of predominately palisade cells throughout;
• thallus 2-3 (5) cells thick except where localized development of erect filaments occur and where concptacle initiation is taking place;
• pore canals of tetrasporangial conceptacles lined by cells that arise from filaments interspersed among sporangial initials;
• these cells do not protrude into the pore canal, and are oriented more-or-less perpendicularly to the roof surface;
• tetrasporangial conceptacle lacking a columella.

ETYMOLOGY: Lithoporella, from the Greek lithos (stone), poros (pore) and ellus (used to form diminutive)
KEY FEATURES:Lithoporella is characterised by the following combination of characters: a thallus that is not endophytic and that lacks haustoria; a dimerous thallus with basal filaments composed of palisade cells; a thin thallus [2-3(5) cells] except near points of branching; pore canals of tetrasporangial conceptacles lined by cells that arise from filaments interspersed among sporangial initials; these cells do not protrude into the pore canal, and are oriented more-or-less perpendicularly to the roof surface. In addition, the absence of a columella in the tetrasporangial conceptacles distinguish Lithoporella from Mastophora.

Mastophora Decaisne 1842: 365

• Thallus non-geniculate, non-endophytic, and lacking haustoria;
• thallus possessing a basal layer of predominately palisade cells throughout;
• thallus 2-3 (5) cells thick except where localized development of erect filaments occur and where concptacle initiation is taking place;
• male conceptacles containing simple spermatangial systems that are restricted to the conceptacle floor;
• gonimoblast filaments borne from the margin of the fusion cell
• pore canals of tetrasporangial conceptacles lined by cells that arise from peripheral roof filaments, protrude into the pore canal, and are oriented more-or-less parallel to the roof surface;
• tetrasporangial conceptacle with a columella.

ETYMOLOGY: Mastophora, from the Greek mastos (breast) and phora (that which is borne or carried, referring to the breast-like appearence of the conceptacles.
KEY FEATURES: All of the above characters are diagnostic, but in particular the dimerous thallus with basal filaments composed of palisade cells, and the pore canals of tetrasporangial conceptacles lined by cells that arise from peripheral roof filaments, protrude into the pore canal, and are oriented more-or-less parallel to the roof surface. In addition, the columella in the tetrasporangial conceptacles distinguish Mastophora from Lithoporella.

Metamastophora Setchell 1943: 130

• Thallus non-geniculate, non-endophytic, and lacking haustoria;
• thallus arborescent (tree-like) and flabelliform (fan-shaped) in growth form, and anchored to the substratum by a distinct holdfast and stipe;
• thallus dimerous;
• thallus possessing a basal layer of predominately palisade cells throughout;
• male conceptacles containing simple spermatangial systems that are restricted to the conceptacle floor;
• gonimoblast filaments borne from the margin of the fusion cell
• pore canals of tetrasporangial conceptacles lined by cells that arise from peripheral roof filaments, protrude into the pore canal, and are oriented more-or-less parallel to the roof surface;
• tetrasporangial conceptacle with a columella.

ETYMOLOGY:Metamastophora, from the Greek word meta (associated with) and the generic name Mastophora.
KEY FEATURES: Metamastophora is the only mastophoroid genus in which the thallus is arborescent (tree-like) and flabelliform (fan-shaped) in growth form, and anchored to the substratum by a distinct holdfast and stipe (see also the melobesioid, Mastophoropsis).

Neogoniolithon Setchell & Mason 1943: 89

• Thallus non-geniculate, non-endophytic, and lacking haustoria;
• thallus lacking a basal layer of palisade cells throughout;
• pore canals of tetrasporangial conceptacles lined by cells that arise from peripheral roof filaments, protrude into the pore canal, and are oriented more-or-less parallel to the roof surface;
• simple spermatangial systems are found on the floor, walls and roof of the male conceptacle;
• gonimoblast filaments arising dorsally from fusion cells.

ETYMOLOGY: Neogoniolithon, from the Greek neo (new) and the generic name Goniolithon
KEY FEATURES: Neogoniolithon is the only mastophoroid genus in which simple spermatangial systems are borne on the floor, walls and roof of the male conceptacle.

Spongites Kützing 1841: 30

• Thallus non-geniculate, non-endophytic, and lacking haustoria;
• thallus lacking a basal layer of palisade cells throughout;
• pore canals of tetrasporangial conceptacles lined by cells that arise from peripheral roof filaments, protrude into the pore canal, and are oriented more-or-less parallel to the roof surface;
• male conceptacles containing simple spermatangial systems that are restricted to the conceptacle floor;
• gonimoblast filaments borne from the margin of the fusion cell.

ETYMOLOGY:Spongites, from the Latin spongia (sponge), probably referring to the superficial resemblance of some Spongites thalli to sponges.
KEY FEATURES: One of the main features of Spongites is the fact that the pore canals of tetrasporangial conceptacles are lined by cells that arise from peripheral roof filaments, protrude into the pore canal, and are oriented more-or-less parallel to the roof surface.

Pneophyllum Kützing 1843: 385

• Thallus non-geniculate, non-endophytic, and lacking haustoria;
• thallus lacking a basal layer of palisade cells throughout;
• cells of adjacent filaments joined by cell fusions;
• tetrasporangial roof developing from filaments interspersed among, as well as filaments surrounding the sporangia;
• pore canals of tetrasporangial conceptacles lined by cells that are oriented more-or-less parallel to the roof surface and may protrude into the pore canal;
• male conceptacles containing simple spermatangial systems that are restricted to the conceptacle floor;
• gonimoblast filaments borne from the margin of the fusion cell.

KEY FEATURES: One of the main features of Pneophyllum is the fact that the tetrasporangial roof develop from filaments both interspersed among and surrounding the sporangia; and the pore canals of tetrasporangial conceptacles are lined by cells that are oriented more-or-less parallel to the roof surface and that may protrude into the pore canal.

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Derek Keats,
updated 02/01/01