P. fragilis may refer to: Pentachaeta gracilis, a plant species in the genus Pentachaeta endemic to California Polysiphonia fragilis, a red alga species Phreatogammarus fragilis, an amphipod species found only in New Zealand's South Island Synonyms Pleurothallis fragilis, a synonym for Acianthera luteola, an orchid species See also Fragilis (disambiguation)