Reshnee Lalla
South African National Biodiversity Institutes’ Invasive Species Programme (ISP)*
with inputs from Lorraine Strathie
Agricultural Research Council-Plant Protection Research Institute (ARC-PRRI)
P
arthenium hysterophorus (locally
called Famine Weed, Parthenium,
Demoina Weed and Umbulalazwe),
is an annual herbaceous plant.
Famine Weed has invaded the northern and
eastern regions of South Africa and many
countries along the eastern seaboard of Africa
and is also a widespread invader in Asia and
Australia. It spreads at a rapid rate due to several factors including climatic suitability, prolific seed production, and the unintentional
facilitation of seed spread via vehicles, machinery, water, animals and various other human-related activities.
Parthenium hysterophorus causes a range of
impacts, from human and animal health effects to biodiversity loss, and massively reduces animal and crop agricultural production. It
causes severe economic losses in many areas
where it has invaded around the world, impacting in particular on the livelihoods of subsistence farmers and rural communities.
Health complications may arise from the allergic reactions displayed by many people who
have frequent exposure to the plant.
South Africa has realized the severity of Famine Weed and in 2014 produced the National
Strategy for the Management of Famine
Weed, and an associated National Implementation Plan to facilitate coordinated management of this species at national, regional and
local levels (accessible at www.issa.org.za).
Chemical control is being used to reduce the
spread, by targeting outlier populations. However, the main effort is going into biological
control to reduce the species’ invasive potential in the long term.
As budget is limited and the control teams
dealing with Famine Weed in outlying areas
often need to travel long distances to spray
these outliers, the correct identification of the
plant is critical. Due to occasional confusion
with plants of the closely related Ambrosia
genus also present in South Africa, a basic
Identification guide to distinguish Famine
Weed from Ambrosia species (especially when
plants are very young and not yet flowering)
was developed.