A Grammatical Dictionary of Botanical Latin

third: tertius,-a,-um (adj.A, an ordinal number);

 
       m.       f.       n.         m.       f.        n. 
Nom. tertius  tertia   tertium   tertii    tertiae   tertia 
Gen. tertii   tertiae  tertii    tertiorum tertiarum tertiorum < 
Acc. tertium  tertiam  tertium   tertios   tertias   tertia 
Dat. tertio   tertiae  tertio    tertiis   tertiis   tertiis 
Abl. tertio   tertia   tertio    tertiis   tertiis   tertiis

- cellula (s.f.I) tertia, the third cell.

- valva,-ae (s.f.I) tertia, third valve.

- diebus tertiis, every three days.

- speciei tertii similis, similar to the third species.

- notis speciei tertius distinguenda, to be distinguished by the features of the third species.

- filamenta in parte tertia basali tubi inserta, filaments inserted on the basal third part of the tube.

- inter diem secundum et tertium, during or within the second and third day

- flores feminei in 3 bracteis foliaceis inclusi, bracteam primam extimam vagina 13-15 mm longa, bracteam secundam vagina ca. 16-22 mm longa, bracteam tertiam vagina 14-20 mm longa; female flowers included in 3 foliaceous bracts,first outermost bracts with a sheath 13-15 mm long, second bract with a sheath ca. 16-22 mm long, third bracht with a sheath 14-20 mm long.

Note: Stearn (1983) apparently erroneously indicated that the ordinal numerals primus, secundus and tertius are declined like the irregular adjective and cardinal number ‘unus’, i.e. with the genitive singular ending in -ius, and the dat. sg. in -i in all genders. Unfortunately this is not the case. All ordinal numerals are declined as regular A adjectives (gen.sg. -i (m.) -ae (f.), -i (n.), etc.).

a third part, a third: tertiarium,-ii (s.n.II), abl. sg. tertiario; triens,-entis (s.m.III), q.v., abl.sg. triente (a noun), a third part, a third of anything;

- tertiario folii glabro, with the third part of the leaf glabrous.

- caule solum in triente supera foliato, with the stem only in the upper third part foliate.