Indigenous medicinal plant knowledge is crucial in the science of pharmacology and the discovery of useful medications. Plants have long been thought to be the most promising treatment for many ailments, and they play an important role in the healthcare of numerous indigenous people around the world (Mechaala et al., 2021). The presence of diverse phytochemicals such as alkaloids, phenolics, flavonoids, terpenoids, and so on contributes to medicinal plants' enhanced nutraceutical characteristics (Torres-León et al., 2023). Through ethnobotanical surveys, a variety of plant-based medications have been produced and introduced. Some of the commercially valuable secondary metabolites isolated based on the traditional medications are reserpine (Rauvolfia serpentina Benth. ex. Kurz), vinblastine and vincristine (Catharanthus roseus (L.) G. Don), teniposide (Podophyllum peltatum L.), paclitaxel (Taxus baccata L.), atropine (Atropa bella-donna L.), artemisinin (Artemisia annua L.), and camptothecin (Camptotheca acuminata Decne.) (Khan and Ahmad, 2019).

Plant-based crude pharmaceuticals are extensively used by people in rural regions who do not have easy access to modern allopathic medicines because they are less expensive, have cultural significance, are more effective, and have less adverse effects than synthetic drugs (Ayyanar and Ignacimuthu, 2011, Nyagumbo et al., 2022). Folk medical knowledge is normally passed down from generation to generation, but it is presently being destroyed because to a lack of interest among the younger generation (Cordero et al., 2023). The degradation of ethnic medical knowledge not only has an impact on the development of new therapeutic treatments, but it also poses a significant risk to rural residents who rely on plant-based medicines (Nguanchoo et al., 2023). As a result, accurate documentation of ethnic knowledge is critical to preventing its extinction from humanity.

Respiratory sickness is one of the most common diseases and has a significant impact on the global health care system, particularly in children under the age of five (Cock and Van Vuuren, 2020a, Rehman et al., 2023). Infections frequently affect the human respiratory system, particularly the bronchi, lungs, and nasal passages, because they are frequently exposed to germs (WHO, 2015). In both developing and developed countries, the prevalence of respiratory disease remains high; it ranks second only to cardiovascular diseases in terms of occurrence, prevalence, and death (Dailah, 2022). Cough, asthma, bronchial diseases, pneumonia, nasal infections, chest and throat pain are some of the most prevalent respiratory illnesses (Haile et al., 2022). According to the WHO, chronic respiratory and chronic obstructive pulmonary disease (COPD) caused around 3.9 million deaths worldwide in all age categories, making it one of the top ten causes of death (Haile et al., 2022). According to World Health Statistics (2022), long-term tobacco uses and exposure to air pollutants, particularly nitrogen dioxide, can induce respiratory illness, particularly wheezing and coughing.

People from many parts of the world use medicinal plants and plant-based medications as a primary remedy for treating respiratory diseases (Savithramma et al., 2007, York et al., 2011, Rigat et al., 2013, Cavero and Calvo, 2014, Silambarasan and Ayyanar, 2015, Alamgeer et al., 2018, Krupa et al., 2019, Sureshkumar et al., 2021, Haile et al., 2022). The purpose of this study was to document the ethnic knowledge of Kani tribals in Tirunelveli district in treating respiratory diseases and to analyze the data collected using quantitative indices of use value (UV), frequency of citation (FC), percentage of use frequency (Fq%), and family use value (FUV). Despite multiple ethnobotanical studies in this region (Ayyanar and Ignacimuthu, 2005, Ayyanar and Ignacimuthu, 2010, Sutha et al., 2010, Jenipher and Ayyanar, 2022), some medicinal plants remain undocumented.