Psidium cattleyanum commonly known as Cattley guava, Strawberry guava or Cherry guava, is a small tree in the myrtle family. Its native range is restricted to the Amazonian basin but has been introduced to many tropical areas including Mauritius, where it is considered an invasive species. It is a small, highly branched tree measuring between 2 and 4 meters. Its bark is smooth, grey to reddish-brown and it has oval leaves that grow to 4-5 centimeters.
Strawberry guava trees thrive in a wide range of habitats ranging from sub-montane rainforest, montane cloud forest, montane rainforest, moist tropical montane forest, tropical ravine/riparian forest, tropical evergreen forest, tropical montane savanna, lowland sub-tropical rainforest, scrub land, grass land, degraded forest, cultivation and agro-forestry areas.
The strawberry guava tree reproduces through seed dispersal and root sprouts, which allow rapid expansive reproduction. The tree bears fruit after 3 to 6 years, which can range in colour from yellow to dark red or purple. Flowers have five petals and grow individually or in clusters of three. The strawberry guava has been shown to have high genetic variation according to elevation and shade-tolerance and is known to withstand soils with moderate to high pH levels. These factors contribute to its invasive quality. In addition, the tree forms dense thickets that crowd sunlight and prevent the growth of native species[1].
Psidium cattleyanum presents many challenges for successful eradication where it is considered invasive: feral pigs and non-native birds contribute to seed dispersal and removing the tree with its roots (which would otherwise produce numerous offshoots) is labour intensive and costly. Nevertheless, some eradication plans have proven to be successful in small areas. In Mauritius, the plant is managed by removing the tree with its roots entirely or cutting the tree and applying systemic herbicide to the stumps.
[1] Global Invasive Species Database (2018) Species profile: Psidium cattleianum. Downloaded from http://www.iucngisd.org/gisd/species.php?sc=59 on 13-08-2018.
Feral pigs help the strawberry guava with the dispersal of seeds, while the guava provide favourable conditions for the animals. This leads to further habitat degradation.