> Not every old botanical journal has yet been copied and indexed on Google books.

Very true, and not to quibble, but of it *was* a truly local name (rather than just someone's jumbled misrecollection of something else), it should still show up somewhere, particularly in the multiple volumes of the Dictionary of American Regional English, which lists many local names for flora and fauna.

In this case, of course, absence of evidence is not proof of absence, but if the name is authentic, its use must have been restricted to very few, very few, perhaps in Brooklyn or Riverside or in Namee's own family.

Your original guess that it's a misrecollection of "amaryllis" my be the best, in spite of the existence of Humilis....