It is the auto correct that I don't want. Just noticed on/off at the top of the screen (I expected it to be on the same line as the function).
In Settings, under Language & Keyboard, in the first section (Language & Spelling Correction), when you select Spelling Correction, ignore the line with text. At the top of the screen there is an On/Off switch.
You can also do it when you are typing and you see the suggestions pop-up below. Tap on the arrow to the right of the suggestions, and you'll get a dialog box that allows you to turn off auto replace.
I use multiple languages, frequent abbreviations and many latin plant names, so Google spell checker is driving me crazy.
I can see it in Settings, but I can't figure out how to turn it off?