Final “missing” endemic plant found on Grand Turk

Story & Photos By B Naqqi Manco, Caicos Pine Recovery Project Manager

The Turks & Caicos Islands have nine species of native plants that are found nowhere else on Earth —they are unique to, or in biological terms endemic to the Turks & Caicos Islands. Of these nine plants, seven are apparent in their habitats or at least well-known—and two are fairly small and obscure.

The endemic Turks & Caicos heather has a high profile as our National Flower. The Caicos Encyclia orchid grows tall and fragrant each summer in its habitat. The silvery silverbush is not necessarily an outgoing plant, but it is fairly common throughout the Salt Islands and the Ambergris Cays. The Lucayan pear cactus is rarely encountered anywhere but East Caicos, but its status as an endemic and even as a valid species is terribly doubtful. The stipitate dog-strangle vine is found only on North Caicos, but is fairly frequent and somewhat weedy there. The Caroline’s Stenandrium is rare but well-studied, and one of our two endemic buttonbushes, the Britton’s buttonbush, is abundant on coastal areas of Middle Caicos and well-mapped. However, two endemic plants evaded detection for decades, even during intense biodiversity fieldwork.

A minuscule forest of slender-stemmed pepper-grass, grows well out of reach of grazing mammals in Grand Turk’s North Wells area.

The capillary buttonbush, described in 1978 from South Caicos and then lost to science for 30 years, was rediscovered by Melanie Visaya and B Naqqi Manco during a Turks & Caicos National Trust seed collection foray on South Caicos. Later exploration in 2010 with the Department of Environment & Maritime Affairs (DEMA) and Royal Botanic Gardens, Kew led to its discovery in East Caicos for the first time. Its seeds have been collected for indefinite conservation storage in Kew’s Millennium Seed Bank, a facility where seeds are kept as an insurance policy against plant extinctions in case of catastrophic events of any kind. The majority of our endemic plants’ seeds have been collected and are safely stored, but not all of the plants had been found in order to collect seeds.

A missing-plant mystery that persisted for decades was the presence of slender-stemmed pepper-grass Lepidium filicaule, first described in 1911, collected last in 1975 and then not seen since. Subsequent searches for the plant had proven unproductive. However, during a seed collection field trip to Grand Turk made by DEMA in November 2012, a small population of young specimens of slender-stemmed pepper-grass was discovered near Gun Hill. Additional forays confirmed the presence of the plant on nearby hills and in the area of Breezy Brae and around North Wells, where it was found in flower and fruit.

The DEMA team that made the discovery comprised B Naqqi Manco, Caicos Pine Recovery Project Manager; Jodi Johnson, Environmental Officer, and Peter Lightbourne, Maintenance Supervisor. The identity of the plant would normally be confirmed by the form of flowers and fruits, but the population found was all too young to be fertile. The identity was instead confirmed by leaf shape and the flavour of the leaves—pepper-grasses are true to their names and the slender-stemmed pepper-grass has a milder, sweeter flavour than the common widespread garden weed, wild pepper-grass. (Please note, never taste-sample plants without a qualified botanist to confirm identity!)

The slender-stemmed pepper-grass was later found with flowers and fruits in the North Wells area, and was collected to make an herbarium voucher specimen. In December 2012, seed collections of slender-stemmed pepper-grass were made so that the plant will be protected both within TCI (in DEMA’s Native Plant Biodiversity Conservation Nurseries) and in long term conservation storage at RBG Kew’s Millennium Seed Bank in the UK, a facility that serves as a “Noah’s Ark” for plants.

But where has the slender-stemmed pepper-grass been hiding for the last 37 years? Communication with the Millennium Seed Bank has yielded a suggestion—it is not unknown for some Caribbean plants to exist through most time as seeds, and grow up in abundance only after major rain events (such as Hurricane Sandy in September). A mint-like Salvia endemic to Grand Cayman seems to have the same behaviour, according to the Millennium Seed Bank. If this is the case, it is the perfect candidate for long-term conservation storage.

It may not be much to look at, but the Turks & Caicos Islands endemic slender-stemmed pepper-grass is our very own unique plant and DEMA is working toward ensuring its survival, along with each of TCI’s endemic plant species, now that all have been accounted for!