Fiji boasts a dazzling array of Hibiscus species; read about Dr Lex Thomson’s work to uncover the diversity of these beautiful, yet Critically Endangered, plants…
My journey of discovery of Fiji Hibiscus species started by accident. Early November 2015, I had planned to visit Fiji’s second largest island, off the coast of Vanua Levu, to collect sandalwood DNA samples. However, the boat to transport us never showed up! Rather than waste time in the hot, dusty town of Labasa, our research team decided to undertake some forest botanizing on the nearby Mt Delaikoro. Mt Delaikoro is a protected forest reserve with a locked gate, but as luck would have it, the Forestry Department member of our team Sonu and his father, ex-policeman Deo Dutt, were able to gain access. The forest reserve includes unique Fijian tree species such as Degeneria roseiflora, which is one of two species in an ancient Gondwanan family Degeneriaceae. As the sun was going down we reached the cloud forest near the summit (about 930 m) and were afforded a spectacular view.
We were then delighted to discover- two shrubs of a pink-flowered Hibiscus growing wild. The Mt Delaikoro Hibiscus is a newly described species, Hibiscus bennettii (2019, Pacific Science). The Latin name honours local ethnobotanist John Bennett, who has been assisting with the field work. Following the passage of Cyclone Winston (in 2016), the Mt Delaikoro population of four plants was reduced to only one known individual , and H. bennettii is now Critically Endangered in the wild. Finding these two shrubs is therefore both encouraging and of great significance.
I have also been involved with identifying other Hibiscus species in Fiji; Hibiscus bennettii is a close relative of the Fiji endemic Hibiscus storckii which occurs (or occurred) on the other side of the Somosomo strait on the island of Taveuni in 1865. As part of the Mohammed bin Zayed Species Conservation Fund (MBZ) BGCI research project H. storckii, a species ‘lost to science’, was re-discovered in gardens on Taveuni but no plants were found growing in the wild. In recent times Hibiscus storckii has been confused with H. cooperi (and indeed most photos on the internet and in botanic gardens which purport to be H. storckii are in fact of H. cooperi).
A deeper pink-petalled form of H. storckii was spotted in March 2019 in a village garden in Urata (through research supported by Stanley Smith), near Savusavu, aka Fiji’s Hidden Paradise. This is an important discovery as this Critically Endangered species was unknown to have any morphological variation.
I undertook a review of Fiji Hibiscus species in collaboration with Dr Luca Braglia (Institute of Agricultural Biology and Biotechnology, CNR, Milan) where we described two additional new species of Hibiscus – H. macverryi from Taveuni and H. bragliae from the island of Ovalau, both species are also Critically Endangered in the wild due to extreme climatic events and invasive alien plant species.
I have funding with BGCI, from the Stanley Smith (UK) Horticultural Trust, to investigate H. macverryi further in Vanua Levu (known here only from a single specimen collected in 1923). We are also researching the Fiji White (which appears to be an undescribed species).
Fiji White is one of the most morphologically distinctive and beautiful Hibiscus, with multi-coloured narrow petals and divided mature foliage . Fiji White is only known in cultivation in Hawai’i/USA, Japan and Australia but exciting leads suggest that the species may still exist in the wild in Fiji, in remote locations in the interior of the main island of Viti Levu. The journey continues……