The settlement of St Helena and the consequent introduction of goats (Capra hircus) led to a decline in the Scrubwood population and the species became confined to refuges on the cliffs, where the Goats could not reach the plants. Extirpation of feral livestock led to re-colonization of a few slopes from the 1960s onward. In particular, the Turk’s Cap subpopulation increased from 10 plants in 1986 to 325 in 2014. At Blue Point, numbers may well also be increasing naturally, especially at Distant Cottage; observations by local conservationists assert that the species has expanded substantially from cliffs refuges onto the adjacent plateau over the past 30 years. However, at other sites Scrubwood numbers have almost certainly declined, most heavily at Flagstaff and Powell’s Valley where competition from invasive weeds has resulted in considerable habitat degradation. The colonies at Cole’s Rock and in Turk’s Cap Valley are also likely to be under threat, with little recruitment.
Scrubwood is very sensitive to grazing as the leaves do not regenerate once shoots have been grazed. Present grazing threats include rodents (particularly Mice (Mus musculus) which feed on the gummy petiole bases), Rabbits (Oryctolagus cuniculus) and feral livestock (mainly Sheep, Ovis aries); these pose a severe threat to the population if not controlled. There is also aggressive competition in some areas from invasive species such as Wild Mango (Schinus terebinthifolia Raddi), Tungy (Opuntia elatior Mill. and O. ficus-indica (L). Mill.) and Creeper (Carpobrotus edulis (L.) N.E.Br.) which is highly likely to be the cause of future continuing decline to the extent and quality of Scrubwood habitat. African Fountain Grass, a competitive non-native species which excludes competitors by forming dense monocultural stands, also poses a significant threat for future Scrubwood habitat. Fountain grass is spreading rapidly across the south-western part of St Helena and presents an imminent threat to the main strongholds at Man & Horse and Blue Point.
One subpopulation has sustained some losses through damage resulting from the construction of the island’s new airport, though with construction almost complete this activity is not a long-term threat to the population.
There is also concern over the potential threat of hybridization of this species with the Gumwood (Commidendum robustum (Roxb.) DC.); however, the rate of introgression appears to be low and the species grow (or recently grew) together at two entirely wild localities with most specimens remaining apparently pure bred.