Stockwellia

''Stockwellia'' is a monotypic genus in the flowering plant family Myrtaceae. The sole species in the genus, ''Stockwellia quadrifida'' (commonly known as Vic Stockwell's puzzle), is endemic to Queensland.

Description

''Stockwellia quadrifida'' is a very large rainforest emergent, growing up to tall and DBH. It has straight boles with reddish-brown flaky bark and buttress roots up to high.

The leaves are opposite to sub-opposite, glabrous, elliptic and leathery, measuring up to long by wide and turning red before falling.

Inflorescences are axillary, produced in groups of three sessile flowers on a peduncle measuring in length. The fruits are a fused woody capsule containing oval-shaped seeds measuring up to .

Discovery

This species first became known to botanical science in 1971, when Atherton resident Keith Gould began experimenting with aerial photography as a means of forestry interpretation. Some of his photos appeared to show a large group of emergent trees in a small patch of rainforest near Topaz, and he referred them to Victor (Vic) Stockwell who was Queensland Forestry's ranger responsible for managing timber harvesting in that area. Despite Stockwell's vast experience in forestry he was unable to identify the trees from the photos, and so the two men ventured on foot into the forest to find them. When they encountered the trees, Stockwell realised that this was a species unknown both to himself and to botany in general.

Stockwell was surprised to discover a tree (especially a tree so massive, and growing close to forestry roads) of which he was unaware. It quickly aroused interest in botanical circles and became known colloquially as "Vic Stockwell's Puzzle", and was even mentioned in a scientific paper as ''Stockwellia'' long before a formal description and name was published.

Distribution and habitat

This species is endemic to a very small part of the luxuriant Wet Tropics rainforests of north-eastern Queensland, specifically an area on the western slopes of Mount Bartle Frere where it is found only in well-developed rainforest. It occurs within an altitude range of about . The area of occupancy of this species is just .

Taxonomy

The genus ''Stockwellia'' and the species ''S. quadrifida'' were first formally described in 2002, some thirty years after its discovery. The Australian botanists Denis John Carr, Maisie Carr and Bernard Hyland published their collaboration in the ''Botanical Journal of the Linnean Society'', based on material collected by Hyland.

Phylogeny

Genetic studies have shown that ''Stockwellia'' belongs in the "Eucalyptopsis alliance" (along with the genera ''Eucalyptopsis'' and ''Allosyncarpa'') and that ''Allosyncarpa'' is basal to this group while the other two are sister taxa. The closest relatives, therefore, are '' Eucalyptopsis alauda'' and '' Eucalyptopsis papuana '' (both from New Guinea and the only two species in the genus), and '' Allosyncarpia ternata'' (another monotypic genus) from the Northern Territory.

Etymology

The genus name is in honour of Vic Stockwell, being the first to identify the plant as an unknown species. The species epithet ''quadrifida'' is derived from the Latin '' quattuor'' (four), and ''-fidus'' (divided), referring to the four segments of the hypanthium.

Conservation status

This species is listed by the Queensland Department of Environment and Science as vulnerable. , it has not been assessed by the IUCN.

In the 2002 paper that formally describes ''S. quadrifida'', the authors stated that despite its restricted range the only threat to the species is predation of the seeds by sulphur-crested cockatoos (''Cacatua galerita''). However a new threat has recently appeared that may be of concern. The Australian botanist Andrew Thornhill wrote in an informal (i.e. not peer reviewed) article in The Conversation that he and fellow botanist Stuart Worboys recently visited these trees, at which time Worboys observed evidence of the fungus myrtle rust on the leaves. Thornhill wrote: suggesting that the status of this newly discovered species may change in the future.

Ecology

The seeds are eaten by sulphur-crested cockatoos.

Gallery

File:Stockwellia-quadrifida-ALA-1.jpg, Inflorescence
File:Stockwellia-quadrifida-ALA-3.jpg, Flower
File:Stockwellia-quadrifida-SF23300-01.jpg, Base of tree
File:Stockwellia-quadrifida-SF23300-02.jpg, Trunk with buttresses
File:Stockwellia-quadrifida-SF23300-05.jpg, Trunk and canopy

References

Notes

External links

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View a map
of historical sightings of this species at the Australasian Virtual Herbarium

View observations
of this species on iNaturalist

View images
of this species on Flickriver

Photographs
by Don Franklin, Jan 2013.

{{Taxonbar, from=Q6134379

Myrtaceae
Monotypic Myrtaceae genera
Endemic flora of Queensland
Taxa named by Maisie Carr
Taxa named by Bernard Hyland