The Plants and Trees of Saint Brandon

NATIVE SPECIES

Tournefortia argentea (Veloutier) and Scaevola taccada (Sea Lettuce)

The two dominant native shrubs of the archipelago. They are found on every vegetated island, almost always together, forming the dense, salt-tolerant low cover that is the foundational vegetation type of Saint Brandon. Tournefortia — also known by its older name Arguisia and locally as veloutier — has silvery-green, fleshy leaves adapted to high salt and strong sun. Scaevola, sometimes called sea lettuce, has the brighter green leaves and the distinctive half-flower bloom from which the genus takes its name. Together they hold the islands together. Most of the bird-nesting habitat in the archipelago is built on these two species, and their loss to invasive plants or guano-mining is the single biggest terrestrial conservation issue at Saint Brandon.

Suriana maritima (bay cedar)

Native, found in association with Arguisia and Scaevola. The ‘sand-flower’ that I counted nine specimens of on the L’île du Sud sandbar.

Pemphis acidula

A native shrub of the windward shoreline, more drought-tolerant than the Arguisia-Scaevola association. Found on the more exposed northern and eastern faces of several islands.

Coconut palm — Cocos nucifera

Considered native to the Indo-Pacific generally, including Saint Brandon. Scattered groves on Coco and the inhabited islands. Eight mature individuals counted at Coco’s centre during our visit. The coconut palm is one of the few species at Saint Brandon that produces meaningful food for human inhabitants.

Coconut palm — Cocos nucifera

Considered native to the Indo-Pacific generally, including Saint Brandon. Scattered groves on Coco and the inhabited islands. Eight mature individuals counted at Coco’s centre during our visit. The coconut palm is one of the few species at Saint Brandon that produces meaningful food for human inhabitants.

Cassytha filiformis (dodder laurel)

A native creeper that attaches to host plants and slowly draws nutrients from them — semi-parasitic, not strictly parasitic, as it photosynthesises on its own. In balanced ecosystems it sits modestly within the vegetation. In stressed ecosystems it can spread rapidly and choke out the underlying shrubs. The plant I saw most consistently across Saint Brandon. The 2019 Cole survey marks it for controlled management — limitation rather than removal, in recognition of its native status.

Ipomoea pes-caprae (Goat’s Foot Morning Glory) and Ipomoea macrantha

Two native morning glory species. I. pes-caprae — the goat’s-foot — is the trailing pink-flowered creeper that pioneers the new ground of accreting sand-cays, its leaves shaped like the cloven hoof that gives it its common name. I. macrantha is the larger white-flowered species. Their presence is a sign that a young sandbar is beginning to stabilise.

Boerhavia coccinea (Hogweed)

A native of the herb-mat layer beneath the Tournefortia–Scaevola canopy. Small pinkish flowers. Soft, springy ground cover, the substrate on which several seabird nesting colonies depend.

Dactyloctenium aegyptium (Crowfoot Grass), Achyranthes aspera (Devil’s Horsewhip), Mukia, Sesuvium ayresii (Shoreline Sea Purslane)

The other herb-mat species. Dactyloctenium forms the mat itself — a low grass that holds the soil against wind. Achyranthes is interspersed through it. Sesuvium — the shoreline sea purslane — colonises the wetter areas closer to the high-tide line.

Thespesia populnea (Pacific Rosewood)

A native tree with heart-shaped leaves and yellow hibiscus-like flowers, found in coastal areas across the Indo-Pacific. Present at Coco and Île Raphael.

INTRODUCED SPECIES — PRESENT AND PRIORITY FOR REMOVAL

Casuarina equisetifolia (Filao)

The “she-oak” or “ironwood.” Non-native to Saint Brandon, introduced as windbreak and timber at multiple points in the early twentieth century. Survives cyclones well, but acidifies the soil, out-competes native vegetation, and — most damagingly — accelerates coastal erosion in the low-lying coastal zones where it has been planted. The 2019 Cole survey marks it for managed removal. Removing it, however, is more politically difficult than introducing it was, because the trees are large, mature, and visually defining of the inhabited islands.

Gossypium herbaceum (Cotton)

Non-native, introduced — most likely during the colonial period — and now self-sustaining on parts of Coco and several other inhabited islands. The cotton plant at Saint Brandon grows as a sturdy shrub, with the familiar splitting bolls that release the white fibre when ripe. Flagged for removal in the Cole survey. The cotton is one of the more visible invasive species across the archipelago and one of the easiest to identify when walking the inhabited interiors.

Leucaena leucocephala (False Acacia)

A fast-growing leguminous shrub from Central America, introduced across the tropics as livestock fodder and firewood. Flagged in the Cole survey as highly invasive — remove. False acacia at Saint Brandon outcompetes native shrubs aggressively, fixes nitrogen into soils that have evolved to be nitrogen-poor (changing the chemistry of the substrate in ways that favour further invasives), and produces dense thickets where seabirds cannot nest.

Ficus benghalensis (Banyan)

Three large banyan trees and one new specimen were observed at Coco’s centre during our visit. The banyan is the iconic Indian strangler fig — a tree that begins life as an epiphyte on another tree, then drops aerial roots that fuse around the host and eventually replace it. At Saint Brandon the banyans are mature, large, and beautiful in the cathedral-like way old fig trees can be, but they are also non-native and flagged for removal. They are slow-growing enough that removal is a feasible project over a five-to-ten-year window.

Coccoloba uvifera (Seagrape)

A coastal shrub native to the Caribbean and Central America, introduced widely as an ornamental and as a beach stabiliser. Flagged for removal at Saint Brandon. Easily identified by its large round leathery leaves with reddish veins, and the grape-like clusters of small fruits the plant produces in the summer.

Cordia subcordata (Beach Cordia)

Sometimes called the orange-flower cordia. A medium-sized tree with bright orange tubular flowers. Although native to parts of the Indo-Pacific, it has been introduced to Saint Brandon and behaves invasively. Flagged for removal in the Cole survey.

Terminalia catappa (Indian Almond)

A large coastal tree from South and Southeast Asia, widely planted across the tropics for shade and its edible fruit. Non-native to Saint Brandon and flagged for removal. Easily recognised by its large oval leaves that turn deep red before falling.

Tabebuia pallida (White Cedar)

A flowering tree native to the Caribbean, introduced as an ornamental and now naturalised on several Saint Brandon islands. Flagged for removal.

Desmanthus virgatus (Petit Acacia)

A small leguminous shrub from the Americas, with feathery leaves and tiny white flowers. Naturalised on parts of Coco. Flagged for removal.

Senna occidentalis (Coffeeweed)

A weedy annual from the Americas, naturalised across the tropics. Present at Coco but not flagged as priority — manageable rather than urgent.

Achyranthes aspera (Devil’s Horsewhip)

Although categorised as non-native in the Cole survey, this plant is widespread across the tropics and difficult to remove without disturbing the native herb mat it has interwoven itself with. The survey notes it as difficult to remove, but can be controlled.

Cyperus rotundus (Common Nut Sedge) and Euphorbia hirta (Asthma-plant)

Smaller weedy non-natives present in the inhabited areas. Manageable rather than urgent removal priorities.

INTRODUCED SPECIES — NOT DETECTED AT MOST RECENT SURVEY

The Cole surveys also recorded the historic introduction of a further twelve non-native species — papaya, aloe vera, frangipani, Madagascar periwinkle, vetiver, common purslane, blue porterweed, pongam, passionflower, gulf sandmat, wireweed, and others. None were detected at the 2019 survey. Whether these species were eradicated, never established, or simply not encountered during the survey is unclear. Continued monitoring is required.

MACROALGAE

Halimeda species

A group of green calcareous algae that grows like jointed fronds across the lagoon floor. Halimeda contributes substantially to the sand of Saint Brandon’s beaches — when the algae die, their calcium-carbonate joints break down into beach sand. The 1997 surveys documented six species at Saint Brandon: H. discoidea, H. microlobata, H. macroloba, H. monile, H. opuntia, and one unidentified.

Coralline red algae

The rust-and-pink crusts on dead coral and reef-rock that bind the reef-flat together and build the algal ridge along Saint Brandon’s seaward edge. One of the longest such ridges in the Indian Ocean.

Caulerpa, Jania, Symploca, Peyssonelia

Other algal genera documented at Saint Brandon, mostly as understory or substrate cover across the lagoon and reef habitats.

Editorial & Commissioned Work

If you would like to be in touch — for editorial commissions, place writing, long-form journalism, or design and brand work — write to me at river@welovethesea.co

I am available to be sent to places. I take a small number of commissions a year, for editors, publications, and brands who want a particular kind of attention paid to a particular place. Travel writing in the conventional sense is not what I do. My work is written from inside a place rather than across the surface of it, paired with original research and field notes from the ground.