A Grammatical Dictionary of Botanical Latin

quaterni,-ae,-a (adj.A, plural only), gen. pl. quaternum (Lewis & Short): four, four each, in or by fours, four at a time; four together, four at once, a set of four; “growing in fours” (Lindley); cf. quaternarius,-a,-um (adj.A); cf. solitarius,-a,-um (adj.A), bini (2), quaterni (4), quini (5), seni (6), septeni (7), octoni (8); see -ni;

        (singular)                  plural   
                              m.       f.        n.   
Nom.  (there is no)        quaterni quaternae quaterna   
Gen.     (singular)               [quaternum]   
Dat.                               quaternis     
Acc.                    quaternos quaternas quaterna   
Abl.                               quaternis

NOTE: there is no singular (e.g. quaternus,-a,-um (adj.A).

NOTE: there is no quaterniens, or quaternies, four times; see quater (adv.). - [PIPER quadrifolium] foliis quaternis cuneiformibus obovatis émarginatis (Swartz), with the leaves in fours [four together] wedge-shaped, obovate [i.e. with the broadest part at the top], emarginate.

- folia quaterna, in quo verticillo duo longiora, duo breviora, leaves four together, in each whorl two longer, two shorter (Stearn).

- folia verticillata terna vel quaterna, leaves whorled three or four together. (Stearn)

- cellulae binae quaternaeque aggregatae, cells in groups of two and four (Stearn).

- sepala petalaque quaterna, quina vel sena, sepals and petals four, five or six.

- filis geminis vel forsan quaternis, with the filaments doubled or perhaps in fours.

- petala quaterna ad latus superius posita, petals four positioned on the upper side.

- foliis quaternis, with leaves four together.