/ Dictionary / Index P phloem necrosis: Meaning and Definition of Find definitions for: phlo'em necro"sis Pronunciation: [key] — Plant Pathol. Plant Pathol. a disease of the American elm caused by a mycoplasmalike organism, characterized by yellowing and necrosis of the foliage and yellowish-brown discoloration of the phloem. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. phloem phloem ray Related Content Daily Word Quiz: blanch Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language