A Grammatical Dictionary of Botanical Latin

duo, duae, duo (adj.plural num.): two, q.v., the two, both;

"the cardinal numerals unus (1), duo (2) and tres (3) are declined; the others from quatuor (4) to centum (100) are used unchanged whatever the gender and case of the noun which they qualify" (Stearn 1983); cf. 'both;' cf. ambo, ambae, ambo,numerical adj. expressed in plural only and declined like duo, duae, duo: 'both', two together, the two, of objects naturally in pairs, such as hands or the ends of two-ended objects; see pair; see second; see numerals; see twin;

       [no singular]       always plural  
                      m.          f.             n.  
Nom.      -      duo           duae       duo          (always plural)  
Gen.      ----  duorum      duarum    duorum  


Dat.      ----  duobus       duabus    duobus       'the two; both'  
Acc.      ----  duo or duos  duas     duo  
Abl.      ----   duobus       duabus   duobus

NOTE: the genitive plural may also be written duum.

NOTE: the nom./acc. neuter pl. may also be written dua (Lewis & Short).

NOTE: duo, duae, duo represent the cardinal number ‘two.’

secundus,-a,-um (adj.A) represents the ordinal number (numeral) ‘second.’

NOTE: 'two' (duo, duae, duo) in the sense of 'both' refers to two unrelated or unassociated objects, that is, not usually associated in pairs; see 'both';

- interdum antheridia duo per oogonium visa, sometimes two antheridia per oogonium seen.

- lodiculae duae hyalinae truncatae vel bilobatae glabrae, 1-3 mm longae, lodicules 2 hyaline truncate or 2-lobed glabrous 1-3 mm long (Stearn).

- [two: coloniae aetate duarum vel trium hebdomadum, colonies at the age of two or three weeks, 2- or 3-week-old colonies (Stearn, 1983).

- per duos vel tres menses, for two or three months [mensis,-is (s.m.III)].

- infra stamina duo brevia, below two short stamens

- antheriidia per oogonium unica vel raro duo.

- foliis duobus inferioribus duplo minoribus, acumine magis reflexo (DozyMoek), with the two lower leaves two times smaller, with the acumen more completely reflexed.

- species ad 20, omnes Australienses duabus exceptis, altera Novae Zelandiae, altera Ins. Philippinensium incola (B&H), species to 20, all Australian except two, the one of New Zealand, the other a denizen of the Philippine Islands.

- germinibus duobus concretis velutinis 3-4 gemmulatis (F. Mueller), with the ovaries two, grown together, velvety, 3-4-ovulate.

- innovatio e duobus internodiis constans, quarum alterum breve duo cataphylla (Nieder-blaetter Germanorum) opposita cito decidua, alterum longum duo euphylla (Laubblaetter Germanorum) fert, new shoot composed of two internodes, of which the short one bears two opposite deciduous [i.e. quickly falling] cataphylls (Niederblaeter of the Germans), the other two true leaves (Laubblaetter of the Germans) (Stearn) [‘fert’ = ‘it bears’].

- Choisyus haec duo jungit sub nomine Laplaceae, quam, adjecta tertia specie Asiatica cum quarta Cubensi, a Haemocharicle, Salisb., distinguit, sed character nos effugit (B&H), Choisy joins these two [sc. genera] under the name Laplaceae, which, he distinguishes, having added a third Asiatic species with a fourth Cubean one, from Haemocharide, Salisb., but the character [i.e. distinguishing mark] escapes us.

- sectiones quatuor a Candollio propositas in duas commode jungeres lobis dorso cornigeris (B&H), four sections proposed by Candolle suitably joining into two by the lobes cornigerous on the back.