One of the fruit I buy from time to time is physalis (aka Cape Gooseberry, I’m told). But I really don’t know how people pronounce it.
I say it to myself as faɪˈseɪlɪs, and that’s what I put in LPD.
But the OED gives us a whole range of possibilities:
Pronunciation: Brit. /ˈfʌɪsəlɪs/ , /ˈfɪsəlɪs/ , /fʌɪˈseɪlɪs/ , /fʌɪˈsalɪs/ , U.S. /ˈfaɪsələs/, /ˈfɪsələs/, /ˌfaɪˈsæləs/
So it’s one of those scientific terms on whose spelling we agree, but on whose pronunciation there is no agreement (blog, 1 Mar 2007).
For what it’s worth, the Greek etymon, ϕυσαλλίς ‘bladder’, has a long upsilon. But you only have to consider dynamo, dynamic, and hyper- (all with short upsilon) to see that Greek vowel length is no predictor of the English vowel length.
Interestingly, the Greek word also has double lambda, so that the word 'ought' to be physallis, which would no doubt have penultimate stress and æ.
I wonder what the supermarket produce buyers call it. Or, for that matter, the farmers who grow it.