A Grammatical Dictionary of Botanical Latin

-yx: nouns ending in –yx (sg. m/f III); cf. –ys, nouns ending in -ys; cf. nouns ending in -yxis,-idis [i.e. -yxis,-yxidis].

1. Greek nouns rendered in Latin Third Declension as -yx, gen. sg. -ychis: bostryx,-ychis (s.m.III) [Gk. bostryx, gen. sg. bostrychos (s.m.II), (note Gk. letter 'xi' of nominative becomes chi in the other cases)];

        singular         plural            singular     plural
Nom.    bostryx        bostryches     Nom.  Bostryx       -
Gen.    bostrychis     bostrychum     Gen. Bostrychis     -
Dat.    bostrychi      bostrychibus   Dat.  Bostrychi     -
Acc.    bostrychem     bostryches     Acc. Bostrychem     -
Abl.    bostryche      bostrychibus   Abl.  Bostryche     -

Bostryx,-ychis G. Targione-Tozzetti, a genus of algae.

2. Latin nouns of the Third Declension ending in -yx, gen. sg. -ycis;

         singular       plural
Nom.    calyx       calyces             calyx (s.m.III),-ycis
Gen.    calycis     calycum
Dat.    calyci      calycibus
Acc.    calycem     calyces
Abl.    calyce      calycibus

3. Latin nouns of the Third Declension ending in –yx, gen.sg. –ygis;

Phryx (s.m/f III), gen.sg. Phrygis: a Phrygian.

         singular             plural
Nom.    Phryx            Phryges          Phryx, gen.sg. Phrygis (s.m.III)
Gen.    Phrygis (-os)   Phrygyn
Dat.    Phrygi            Phrygibus
Acc.    Phrygem (-a)   Phryges (-as)
Abl.     Phryge          Phrygibus

NOTE: This paradigm fluctuates in certain cases, e.g. between the Latin and Greek forms: Phrygis, (os), Phrygem, (-a).