Ecological novelty becomes a public problem before it becomes a planting prescription. This study transforms the abstract category of Novel Urban Ecosystems into two socially intelligible distinctions: native/non-native and cultivated/spontaneous. An online questionnaire, pre-tested with eight experts and completed by 203 Portuguese landscape professionals, examines the acceptability of their combinations. Native and cultivated plants enjoy stronger acceptance than non-native and spontaneous ones; notably, a short explanation of ecological novelty raises ratings for some initially less accepted categories. Classification here is not a passive descriptive step: it conditions what the respondent is prepared to recognise and endorse. The experiment makes a methodological difficulty visible as well. These are professional judgements elicited through a questionnaire, not residents' situated responses during movement through actual landscapes. What changes under an altered description is not necessarily what changes under embodied encounter. The paper joins landscape architecture, environmental perception, classification and the sociology of expertise, opening a gap between ecological function, professional legitimacy and lived experience.
