St Helena rosemary (Phylica polifolia)

KingdomPlantae
PhylumTracheophyta
ClassMagnoliopsida
OrderRhamnales
FamilyRhamnaceae
GenusPhylica (1)
SizeHeight: up to 3 m (2)

Classified as Critically Endangered (CR) on the IUCN Red List (1).

This extremely rare shrub gains its common name from the resemblance of the small leaves to those of the herb rosemary (Rosmarinus officinalis), although they are not related (2). It was previously known as a tree (even one that produced useful timber), but only straggling bushes of this species are now seen. These bushes have many slender branches and the tiny leaves are extremely small and pointed with a waxy, dark green sheen to their leathery upper surface (2). The small, greenish-white flowers are either solitary or occur in small clusters (2). Pea-sized hard fruits develop, which contain shiny black seeds (2).

Endemic to St Helena in the southern Atlantic Ocean, this species was previously widespread in the west of the island (2). Today, around 100 plants remain, restricted to three subpopulations on cliffs such as High Hill, Lot and between Distant Cottage and the Asses Ears (4). Records in 1875 by Melliss found the species at Fairyland, Plantation, Rosemary Hall, Oaklands and Lot (4).

Formerly widespread in dry places in the west of the island; Rosemary Plain derives its name from the former occurrence of this plant there (4). The St Helena rosemary is now reduced to small populations on cliffs at 500 - 600 metres above sea level (4).

Flowers are thought to appear in October with fruits maturing from November to January (2). The High Hill and Distant Cottage plants which are found growing out of cliff/rocky outcrops are spreading in habit whereas the plants growing at Lot are upright (4). These differences are also expressed at the molecular level, and have been maintained when planted at the Environmental Conservation Section Nursery in Scotland, St Helena (4).

The island of St Helena has undergone a dramatic loss of native fauna and flora following centuries of exploitation; over 60% of the island has suffered massive erosion or is colonised by introduced plant species (3). Although there are around 100 rosemary plants remaining, these are mainly in small, highly fragmented and genetically distinct populations. Growing on or below rock outcrops, the populations are vulnerable to chance factors and to competition from introduced plants. No regeneration has been observed at the High Hill site in the last 10 years (4).

The Environmental Conservation Section nursery at Scotland, St Helena has raised a number of plants of St Helena rosemary, and some of these have been planted out in private gardens to aid their survival (2).

For more information on St Helena see:

Authenticated (30/6/03) by Rebecca Cairns-Wicks. Chair, IUCN SSC South Atlantic Island Plant Specialist Group.

  1. IUCN Red List (April, 2011)
    http://www.iucnredlist.org/
  2. Cronk, Q.C.B. (2000) The Endemic Flora of St Helena. Anthony Nelson, Shropshire.
  3. Cairns-Wicks, R. (June, 2003) Pers. comm.
  4. Joint Nature Conservation Committee (JNCC) (March, 2003)
    http://www.jncc.gov.uk/international/pdf/St%20Helena.pdf