The word "sternellum" is a botanical term used to describe a small, flattened structure on the underside of the fern frond. The IPA phonetic transcription for "sternellum" is /stə(r)ˈnɛləm/. This spelling reflects the pronunciation of the word, with the stress on the second syllable and the vowel sound in the first syllable being pronounced as a schwa. The spelling of the word also includes a double "l" to indicate that the second syllable is pronounced with an "ell" sound rather than a single "l" sound.