Radiogrammitis cheesemanii 


Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Polypodiopsida Polypodiales Polypodiaceae

Scientific Name: Radiogrammitis cheesemanii
Species Authority: (Parris) Parris
Grammitis cheesemanii Parris
Taxonomic Notes: Radiogrammitis cheesemanii was originally described by Parris (1993) as a new species of Grammitis. Parris (2007) revisited the generic position of many Grammitis and in the process placed Grammitis cheesemanii within a new genus Radiogrammitis. Radiogrammitis ranges from Sri Lanka to Polynesia (Parris 2007).

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(iii)+2ab(iii) ver 3.1
Year Published: 2014
Date Assessed: 2011-04-01
Assessor(s): de Lange, P., Martin, T. & McCormack, G.
Reviewer(s): Sayer, C.
We assess Radiogrammitis cheesemanii as Endangered. The species meets Criteria B1ab(iii)+2ab(iii), based on area of occupancy (AOO) and extent of occurrence (EOO) of 1.5 km2, occurrence at only 3 locations and a continuing decline in habitat.. The species is locally common, but restricted to cloud forest habitats on the island of Rarotonga, which cover approximately 150 hectares (1.5 km2). Invasion of cloud forest by exotic vines has recently begun, and poses a long-term risk if invasion leads to the replacement of indigenous forest and shrubland with vine land.

Geographic Range [top]

Range Description: Radiogrammitis cheesemanii is endemic to the island of Rarotonga (67 km2), Cook Islands.
Countries occurrence:
Cook Islands (Cook Is.)
Estimated area of occupancy (AOO) - km2: 1.5
Number of Locations: 3
Lower elevation limit (metres): 400
Upper elevation limit (metres): 653
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: There is one population, on the island of Rarotonga, Cook Islands. This species is locally common in the cloud forest on Te Kou, Te Manga, and Te Atakura, which occurs at altitudes over 400 m, and covers approximately 150 hectares (1.5 km2).
Current Population Trend: Unknown
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: This species is a small fern that is epiphytic within cloud forest above 400 m asl. This species was commonly found on the trunks and branches of kai’atea (Weinmannia samoensis), pua (Fagraea berteroana), and both Cyathea affinis and C. parksiae.
Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes

Use and Trade [top]

Use and Trade: No trade in this taxon.

Threats [top]

Major Threat(s): This species is primarily at risk from the small area of habitat within which it is found (1.5 km2). However, the key threat to this habitat is invasion by exotic plant species. At present, the invasive vines mile-a-minute (Mikania micrantha) and balloon vine (Cardiospermum grandiflorum) are sparse in cloud forest habitats. These same species are locally dominant on the lower slopes of Rarotonga, where at some locations they have completely displaced indigenous plant communities. It is unknown whether Radiogrammitis cheesemanii has a preference for growing on indigenous species. However, invasion of the cloud forest by exotic vines would pose a risk to this species longer-term, as vines do not provide a suitable substrate for growth of epiphytes.

Conservation Actions [top]

Conservation Actions: No conservation measures are currently in place.

Control of invasive plant species within cloud forest habitat is recommended.

Citation: de Lange, P., Martin, T. & McCormack, G. 2014. Radiogrammitis cheesemanii. The IUCN Red List of Threatened Species 2014: e.T203517A2767289. . Downloaded on 26 November 2015.
Disclaimer: To make use of this information, please check the <Terms of Use>.
Feedback: If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided