Nowadays, it seems that anybody with a ‘smartphone’ can be a plant biologist. Well, not quite – it takes years of dedicated study, etc to be able to claim that right. But, with such technology to hand, almost any member of the public can do their bit to track the whereabouts of ‘problem plants’ (a rather quaint euphemism for invasive, non-native plant species that pose a threat to indigenous wildlife) in the United Kingdom. The UK’s Environment Agency (part of the Department for Environment, Food and Rural Affairs, DEFRA) and the University of Bristol have joined forces to help combat the spread of three particularly problematic plants using the ‘PlantTracker’ app. The ‘Most Wanted’ trio are: Japanese knotweed (Fallopia japonica), Himalayan balsam (Impatiens glandulifera) and floating pennywort (Hydrocotyle ranunculoides). And data on these plants is (sorry, are) important because they pose a threat to biodiversity, increase flood risk and affect the state of the water environment, costing the British economy a minimum of £1.7 billion per annum(!). The PlantTracker app, which is available free from the iTunes App Store and Android Market, shows the user how to identify each species and enables the submission of ‘geo-located’ pictures so that the distribution and spread of these troublesome botanics can be more accurately recorded. However, initially the project is only being piloted in the Midlands (‘the traditional name for the area comprising central England’). Being a tad cynical one might posit that – once rolled out UK-wide – the app will only record the troublesome threesome in areas where there is mobile phone coverage. So, an ideal strategy for a cunning member of this triumvirate is to establish itself in ‘mobile phone blackspots’ where it can live undetected and unbothered by the new age of digital detectives. Whether the ‘app’ could eventually be used in the USA to plot the location – in cell phone-covered areas! – of H. ranunculoides (which is known variously ‘over there’ as floating pennywort, floating marsh-pennywort, and water-pennywort), and whose status is listed as endangered in several States, is not known ( to me…).