“French broom” is the frequent name used for Genista monspessulana (Fabaceae) plant. It is considered as an invasive species in South America (including Colombia) according to the reports made by the International Union for Conservation of Nature (UICN), due to it exhibits a cosmopolitan distribution, effortless propagation and high adaptability. As part of our research on invasive plants, the present work was focused on this plant, aiming to exploit its abundance, toxic features and the well-known background related to high quinolizidine alkaloids contents for species belonging to the same genus, in order to explore the potential employment of its toxic-featured alkaloid-rich extracts (ARE) to be assessed against fungal phytopathogens within a long-term alternative for their control. Thus, seventeen accessions of wild-type Genista monspessulana were collected in the departments of Cundinamarca and Boyacá, Colombia. The collection of plant material considered variables related to the plant growing-environment (human intervention and conservation status). These samples were then processed using a specific acid-base extraction method for alkaloids to obtain the ARE. Resulting extracts were then profiled by GC-MS, in order to determine the presence of various quinolizidine alkaloids (caulophylline, cytisine, aphylline, lehmanine, N-formylcitysine, anagyrine). In addition, the biological activity of the ARE against the phytopathogen Fusarium oxysporum were tested using the amended-agar method and calculated from the mycelial-growth inhibition. All the compiled (chemical and biological) data were analyzed using statistical methods, in particular the unsupervised Principal Components Analysis (PCA) and the supervised Orthogonal Partial Least Squares - Discriminant Analysis (OPLS-DA). In the PCA, the influence variables for explaining the specimen discrimination were those to be extrinsic to the sample – i.e., environment-related – such as observations appreciated during the sampling (intervention status), area of collection (Bogotá, and municipalities from Cundinamarca and Boyacá departments), and the presence of invasive species (Fabaceae, Asteraceae), whilst supervision variables for OPLS-DA were the ARE composition and the antifungal activity against F. oxysporum. Results allowed observing the similarities and differentiation among the 17 specimens, clustering according to similar characteristics, specifically for alkaloid content and inhibition-growth efficacy against F. oxysporum. On this sense, sample 7 (collected in the Sisga reservoir surroundings) exhibited the best mycelial growth inhibition and the major alkaloids diversity. This alkaloidal occurrence could be associated to a competitive response due to the circumambient presence of other plants from Asteraceae and Fabaceae families as well as intervention and activities from humans on location.