A Grammatical Dictionary of Botanical Latin

un-: the negative or contrary expressed in English by the prefix 'un-' is often rendered in Latin comp.:

a) by the prefix in-, or im- before b, m or p;

- inaequus, uneven; indivisus, undivided; incruentus, bloodless; infecundus, unfruitful.

- immaturus, immature; imperfectus, not complete, imperfect.

b) or e- or ex- (before vowels); although in English the 'x' in 'ex-' prefices is often rendered 'ecc-', as in eccentric, in Latin the prefix 'ex-' is retained before 'c': excentricus,-a,-um (adj.A);

- ecostatus, without a costa.

- excavatus,-a,-um (part.A): hollowed out (from cavus, hollow); exsanguis,-e (adj.B), bloodless.

c) or the adverb haud or non;

- haud distinctus, indistinguishable.

d) dis-: in L. comp., q.v., sometimes it is as in the English prefix 'un-' "reversing or negativing the meaning of the primitive (Lewis & Short).

in Greek comp:

a) by the prefix a-, or an- before a vowel [the alpha privitive];

- aphyllus, without leaves; apetalus, without petals; anantherus, without anthers; ananthus, flowerless; anaerobius, able to live without free oxygen.

NOTE: 'non' (Latin) is not a prefix: it is always separated from the word associated with it or which it modifies;

- pileus non albescens, pileus not becoming white.