What is the history and distribution of the two pronunciations of 'lichen' /ˈlʌɪk(ə)n/ and /ˈlɪtʃ(ə)n/?

http://www.oxforddictionaries.com/definition/english/lichen says 'lichen' has two pronunciations: /ˈlʌɪk(ə)n/, /ˈlɪtʃ(ə)n/. In contrast, Oxford English Dictionary only registers the former. What is the history and distribution of these two pronunciations? (Which one do you use and where are you from?)

Solution 1:

The /ˈlʌɪk(ə)n/ pronunciation is completely normal for how Latin words are pronounced in English. When an "i" is in a position where it would be pronounced as a long i in English, it often is: compare item, saliva, sinus, virus. And "ch" in Latin words (which is only found in originally-Greek words) is usually pronounced /k/ in English. Compare echo.

The /ˈlɪtʃ(ə)n/ pronunciation is probably a spelling pronunciation. Somebody reading lichen and never having heard it would be quite likely to pronounce it this way.

I can't find any data as to how these pronunciations are distributed geographically; one could look at the comments and see if there is any pattern. Living in the U.S. Northeast, I almost always hear /ˈlaɪk(ə)n/.

The OED has a note:

The pronunciation /ˈlɪtʃən/ is given in Smart without alternative, and most of the later Dicts. allow it a second place; but it is now rare in educated use.