A Grammatical Dictionary of Botanical Latin

primus,-a,-um (adj.A): (an ordinal number) first, initial, primary; the first of three or more items; initial (opp. secondary, etc.); opp. postremus,-a,-um (adj.A), 'last, final;' (in time or place) first, foremost, the first part; “sometimes to be translated as ‘the end, extremity, as digitus primus, ‘the tips of the finger’ dentes primi, the front teeth, prima lingua, the end of the tongue; first in rank or station, chief, principal, eminent, distinguished, noble; rated first; see primo (adv.).

- prima luna, the new moon.

- primus sol (s.m.III), the rising sun.

- Genera Plantarum, volumen primum, Genera of Plants, first volume.

- pars prima; pars secunda, first part, second part.

first (in a series, in time, in place), initial, primary (an ordinal number): primus,-a,-um (adj.A); see ordinal numerals;

             singular                    plural
         m.     f.       n.      m         f.       n. 
  Nom. primus  prima   primum   primi    primae    prima
  Gen. primi   primae  primi    primorum primarum  primorum
  Acc. primum  primam  primum   primos   primas    prima
  Dat. primo   primae  primo    primis   primis    primis     
  Abl. primo   prima   primo    primis   primis    primis

- prima facie, at first sight; see facies,-ei (s.f.V).

- antheridia solitaria ad furcas secundas et tertias (rarius primas) ramulorum primariorum nonnunquam ad ramulos secundarios posita, antheridia solitary, at second and third (rarely first) forks of the primary branchlets sometimes on secondary branchlets placed (Stearn 1983).

- cellula (s.f.I) prima, initial cell (diatoms).

- valva,-ae (s.f.I) prima, primary valve (diatoms).

- speciei primi similis, similar to the first species.

- gluma prima 0.8--1.8 mm longa, gluma secunda 1.3--2 mm longa.

- 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.

- flores primi et flores postremi, first flowers and last flowers.

- laciniis 5, imbricatis v. subvalvatis (prima juventute semper imbricatis) (B&H), with the lacinia 5, imbricate or nearly valvate (at first youth always imbricate).

a primo: from the beginning, at first.

prima juventute, at the beginning or onset of youth.

in primo: in front, before, in the beginning, first.

prima fronte, at first or initial appearance, at first sight.

- embryo parvus, turbinato-globosus, extra albumen ad basin seminis situs, ideo in fructu inversus, prima fronte indivisus, embryo small, turbinate-globose, situated outside of the albumen at the base of the seed, and for this reason inverted in fruit, at first sight undivided.

primo visu: at first sight;

- species memorabilis Leptodontio Sinensi proxima, colore rubiginoso jam primo visu distincta, a memorable species closest to Leptodontium Sinensis, immediately by the rust-red color distinguished at first sight.

Prima,-orum (n.pl.II): the first part, the beginning; of the first principles or elements of things (Lewis & Short).

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. However this is not the case. All ordinal numerals are declined as regular A adjectives (gen.sg. -i (m.) -ae (f.), -i (n.), etc.).

NOTE: imprimis (adv.), also in primis (adv.): “with or among the first, chiefly, especially, principally, particularly” (Lewis & Short); see imprimis (adv.).