The Mediterranean Grove
Pod, drupe and silver leaf, and three names that came into English through Greek or Latin and kept the letters they arrived with.
These are the dry country trees: the carob with its horn shaped pods, the jujube that crops from the Balkans to China, and the silver leaved oleaster that is not an olive and gets mistaken for one anyway. All three names were written down in Latin before they were ever said in English.
That is the whole problem with them. Latin puts vowels together in ways English does not, ae next to a in Elaeagnus, and it ends words on syllables that English swallows. Between them the three trees account for the longest and the shortest entries on this site.
The trees in this grove
elaeagnus
Elaeagnus angustifolia
el-ee-AG-nus
Linnaeus built the name out of two Greek words, elaia for the olive and agnos for the chaste tree, and the Greek ai came into Latin as ae. That digraph is one sound in English but two letters on the page, and it sits next to a third vowel, so the middle of the word carries three vowel letters for two vowel sounds.
ceratonia
Ceratonia siliqua
seh-ruh-TOH-nee-uh
Greek keras, horn, named the tree for the shape of its pod. Greek k became Latin c, and English then softened that c to an s because an e follows it. So the first letter records a k that has not been pronounced in this word for two thousand years.
jujube
Ziziphus jujuba
JOO-joob
The word reached English through Old French from medieval Latin jujuba, which had already worn the Greek zizyphon down almost past recognition. English kept a final e that it does not pronounce, and that is why half the people who say the word give it two syllables and half give it three.