''Amphibolis griffithii'' is a

seagrass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the orde ...

found in waters along the southwestern coasts of Western Australia, extending to Encounter Bay in South Australia .

Description

A common marine herb, the

rhizomatous In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

plant forms meadows which stabilise sands; the intertwining roots and leaves protects the substrate from ocean currents. The species is perennial, bears its male and female flowers on separate plants, and produces fruit on the leaves. The plant reproduces by viviparous means, the seed germinating before leaving the plant and floating freely. The seedling forms a comb of bristles that can anchor it at the new site before the development of roots and a rhizome allow the plant to fully establish itself. The leaves are arranged at the end of its many branches, attached in an overlapping sheath, and are bright green, perhaps with red patches. These assist in maintaining the meadows cohesion by protecting against erosion from the ocean's currents. Each leaf blade may be up to 75mm long, with a uniform width of 2.5 to 6mm, four or five of the ribbon-like leaves rise upward from the many branches. The form of the sheath, and the longer leaves, differentiate this species from its cogener ', and it is found in rougher oceans than that species.

Distribution

Found along the western coast of Australia, south of

Geraldton Geraldton (Wajarri: ''Jambinu'', Wilunyu: ''Jambinbirri'') is a coastal city in the Mid West region of the Australian state of Western Australia, north of the state capital, Perth. At June 2018, Geraldton had an urban population of 37,648. ...

, and along the southern coastlines to

Victor Harbor, South Australia Victor Harbor is a town in the Australian state of South Australia located within the City of Victor Harbor on the south coast of the Fleurieu Peninsula, about south of the state capital of Adelaide city centre, Adelaide. The town is the large ...

. The occurrence of ' is also recorded near island groups of

Houtman Abrolhos The Houtman Abrolhos (often called the Abrolhos Islands) is a chain of 122 islands and associated coral reefs, in the Indian Ocean off the west coast of Australia, about west of Geraldton, Western Australia. It is the southernmost true coral ...

and the

Archipelago of the Recherche The Archipelago of the Recherche, known locally as the Bay of Isles, is a group of 105 islands, and over 1200 "obstacles to shipping", off the south coast of Western Australia. The islands stretch from east to west and to off-shore encomp ...

. The species is found in areas of fast and constant ocean currents, the rhizomes forming dense mats on soft sand substrates. It is restricted to depths less than 16 metres in its distribution range, and it is often associated with limestone or reef ecologies. The detritus is frequently found in rotting piles along the shoreline, forming a rich habitat for other plant and animal species. The distribution range is smaller than that of ', occupying a narrower range of habitat, possibly due to less tolerance of water temperatures and salinity.

Taxonomy

John McConnell Black provisionally gave this species its name in 1948, the accepted species description was published by

Cornelis den Hartog Cornelis is a Dutch form of the male given name Cornelius. Some common shortened versions of Cornelis in Dutch are Cees, Cor, Corné, Corneel, Crelis, Kees, Neel and Nelis. Cornelis (Kees) and Johannes (Jan) used to be the most common given na ...

in 1970.

References

* * * * {{Taxonbar, from=Q4748210 Cymodoceaceae Angiosperms of Western Australia Flora of South Australia Monocots of Australia