In English-speaking countries, the Botanical Latin places syllable stress for botanical names derived from ancient Greek and Latin broadly according to two systems, either the Reformed academic pronunciation, or the pronunciation developed initially in some large part by British gardeners, horticulturists, naturalists, and botanists of the 19th century.
[1] The two systems differ significantly in pronunciation,α but little in syllable stress.
Diphthongs from Greek can include oi, eu, ei, and ou, and ui also occasionally occurs in botanical Latin.
Botanical Latin does not traditionally include macrons or breves, and they are prohibited (as diacritics) by the International Code of Nomenclature for algae, fungi, and plants (Article 60.6).
Some books follow the mediaeval tradition to add an acute accent to mark the stressed syllable.