Consult one of the best of them, Webster's New World Dictionary, and what you find is a miniature encyclopedia filled with the explanations of initials, proper names, and entries like "macrosporangium" and "abhenry," which are not and never will be words of the English language.    From Wordnik.com.  [VERBATIM: The Language Quarterly Vol XIII No 3] Reference

We have already examined in some detail the structure of the macrosporangium or ovule.    From Wordnik.com.  [Elements of Structural and Systematic Botany For High Schools and Elementary College Courses] Reference

Secondly, the nucleus of the ovule corresponds with the macrosporangium of Selaginella, through the connecting link of the conifers, where the ovule is of similar origin and position to the macrosporangium of the.    From Wordnik.com.  [Scientific American Supplement, No. 531, March 6, 1886] Reference

The development of the ovule, which represents the macrosporangium, is very similar to the process in Gymnosperms; when mature it consists of one or two coats surrounding the central nucellus, except at the apex where an opening, the micropyle, is left.    From Wordnik.com.  [Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1] Reference