Schizaea (Sm.), is a genus of fern native to Western Australia, more commonly known as Comb-ferns. These small, terrestrial ferns are easily distinguished by their dichotomously branching fertile fronds, with spore-cases in a comb-like arrangement at the tip. This genus consists of 28 species worldwide, with three species occurring in Western Australia (Chinnock, 1998).
Schizaea dichotoma (Sm.) is listed as a priority three conservation code on the FloraBase website; this is a poorly-known species and has been recorded in areas not under imminent threat. Schizaea rupestris (R. Br.) is listed as a priority two conservation code on the FloraBase website; this is a poorly-known species and has been recorded in areas not under imminent threat of habitat destruction or degradation.
This genus is currently not threatened within Western Australia.
This genus has not yet been assessed for the IUCN Red List.
Potential threats include ecological disturbances such as fire, changes in soil, changes in canopy, weed invasions and human impact, and disease such as Phytopthora dieback. This genus is comprised of poorly-known species and therefore, the responses to these threats are unknown (Hearn, Meissner, Brown, Macfarlane and Annels, 2006).
The stem grows underneath the ground, along the surface of the ground or leading upwards, and is covered with brown hairs, with little to many fine thread-like roots. The leaves grow in a group, being either fertile (bearing sporangia) or sterile (without sporangia). The stalk of the leaf is difficult to distinguish from the green portion of the leaf, however is normally brown. The green portion of the leaf is whole or axis is divided into two branches 1 to many times, and is rarely leafy and wide. The veins of the leaf do not reunite with other veins. The fertile leaves are alike, where branches end with narrow segments set closely together similar to the teeth of a comb. The spore producing head has alternately arranged segments similar to a feather, with segments that are normally folded. The sporangia are in 2 rows along the segments on both sides of the midrib and are protected by the rounded edge of the leaf blade, normally surrounded with teeth or hairs. The spore surface may be smooth or covered in small ridges. The gametophytes may grow under or above ground. The gametophytes may be fibrous, or modified fibrous, or not have a true axis. The gametophytes may or may not contain chlorophyll.
A link to the genus page within ABRS Flora of Australia Online: http://www.anbg.gov.au/abrs/online-resources/flora/stddisplay.xsql?pnid=...
The genus Schizaea is primarily distinguished by its narrow, forked or dichotomously divided fronds (Chinnock, 1998).
This genus is still poorly known in regards to its evolution due to inadequate sampling, however the fossil record does show that the oldest schizaeoid fern fossils date back to the Middle Jurassic (Pryer et al., 2004).
Kingdom – Plantae
Phylum – Pteriodophyta
Class – Pteridopsida
Order – Schizaeales
Family – Schizaeaceae
Genus - Schizaea
Schizaea belongs to the family Schizaeaceae, which is among the three clades of the schizaeoid ferns (Schuettpelz & Pryer, 2008). The schizaeoid ferns have been separated into three families as they are morphologically so diverse and specialised (Schuettpelz & Pryer, 2008). These ferns have been linked as the sister to the large clade of tree, heterosperous and polypod ferns, known as the core leptosporangiates (Schuettpelz & Pryer, 2008).
In Western Australia, Schizaea dichotoma (Sm.) is distributed in the Northern Kimberley; and Schizaea fistulosa (Labill.) and Schizaea rupestris (R. Br.) are distributed along the South Coast (Spooner, 1997).
A link to the IBRA distribution map within Flora Base of Western Australia: http://florabase.dpaw.wa.gov.au/browse/map/20881
Schizaea thrive in tropical and subtropical environments (Chinnock, 1998). This genus prefers sandy soils and moist areas; growing among rock faces, moss mounds, and sedges and rushes along swamps, creek banks and gorges (Spooner, 1997).
There is no information regarding the relevance or uses of Schizaea.