The use of Alpine Lily (Lilium parvum or related Lilium species) in the treatment of bronchitis is primarily based on traditional and ethnobotanical knowledge rather than scientific validation. Historical records from indigenous communities in North America, particularly some Native American tribes, indicate that various parts of lily plants were used as traditional remedies for respiratory ailments, including coughs and bronchial conditions. The bulbs were sometimes prepared as decoctions or poultices. However, Alpine Lily specifically is not widely cited in ethnobotanical literature compared to other lilies, and comprehensive documentation of its medicinal use is limited.

There is little to no modern scientific research or clinical trials evaluating Alpine Lily's efficacy or safety for bronchitis or any respiratory conditions. No active compounds with known bronchodilatory or anti-inflammatory effects relevant to bronchitis have been isolated from this species in peer-reviewed studies. The evidence rating is therefore low, reflecting that the justification for its use is anecdotal and rooted in tradition rather than rigorous scientific assessment.

To summarize, Alpine Lily's use for bronchitis is supported by limited traditional use with minimal documentation and lacks scientific validation. Its evidence rating for this indication is 1 out of 5.