Heard spelling

periannth

Spelled perianth. a doubled consonant

Two n's or one?

One.

The doubled n in periannth is the ear marking a stress that is not there. The weight of this word sits on the first syllable, and nothing after it is heavy enough to double a letter.

Say

PERR-ee-anth

Letters

P-E-R-I-A-N-T-H