Nathan, thank you for taking the time to explain that. Let me make a counterargument. If, as I think is true, the word "bloom" has as its older and more basic meaning "blossom", then your use of the word "bloom" is itself metaphorical. Even those who would argue that an old, basic meaning of "bloom" refers to "an outward evidence of freshness or healthy vigor" as my Webster's puts it, would probably be aware of the very old connection to the word "blow" in the sense of a flower blooming. So I'm inclined to say that those who use the word to mean "flower" have the older and better established tradition. I'm pretty sure we can say that the meaning "extracuticular wax" is in fact very recent. Isn't it the case that the phrase "extracuticular wax' itself is a modern technical term devised to avoid the age-old ambiguity in the use of the word "bloom". In other words, isn't it likely that the very reason the term "extracuticular wax" exists is to let readers know that flowers are not the intended meaning? You have hit on a growing problem in our use of language. Scientists and those trained in the sciences frequently make a very bad job of it when they attempt to explain what they do for a living, and the reason it turns out to be a bad job is because of the tendency to jump back and forth between literal or everyday meanings of familiar words on the one hand and metaphoric meanings of those same words - often in the same sentence or paragraph. And it's not just scientists who do this: any of us well versed in the jargon of an arcane field is likely to switch back and forth between the use of certain words in a highly specialized sense at one point in a discussion and the use of the same words in their everyday sense within the same discussion. When that happens in presentations intended to explain science to lay people, it's especially disappointing because the lay people remember the metaphor but remain clueless about the actual science. I'll bet this sort of thing gives translators a headache. Jim McKenney Montgomery County, Maryland, USA, USDA zone 7, where the temperature got above freezing for maybe an hour today.