Abstract:
Thapsia garganica is a herbaceous perennial in the Apiaceae, distributed around the
Mediterranean and traditionally used in North Africa as a remedy for arthritis, her pes, hair-fall, hypertension, rheumatic, eczema and scabies. T. garganica is the source
of thapsigargin: known for killing cancer cells. Seven populations were studied in
sites differing in aspect and elevation within Al Jebel Al Akhdar in Libya. We studied
the within-population size distribution of individuals, the timing of the phenological
events, and vegetative and reproductive traits. Thapsia garganica showed high flex ibility of functional traits and shifts in the timing of phenological events in response
to elevation and aspect (north- or south-facing slopes). Local soil properties, together
with effects due to altitude and aspect, could be direct causes of the observed differ ences in terms of population size and phenological traits. The phenological patterns
detected also provide insights into the species response to climate change. Despite
this phenotypic flexibility, and good growth in sites at 300–700 m a. s. l. on south facing slopes, most sites in this study have an unstable size-structure, with few small
individuals. This raises concerns about the long-term persistence of the other popula tions of this species in Al Jebel Al Akhdar.
