A Grammatical Dictionary of Botanical Latin

Hesperis,-idis (s.f.III), abl.sg. Hesperide.

        Singular      plural   
Nom.  Hesperis    hesperides
Gen.  hesperidis  hesperidum
Dat.  hesperidi   hesperidibus
Acc.  Hesperidem  hesperidas [sic?]
Abl.  Hesperide   hesperidibus

Hesperis matronalis (Brassicaceae)

Hesperis,-idis (s.f.III), abl. sg. Hesperide: (classically) “the queen’s gilliflower [i.e. a fragrant flower], Hesperis tristis Linn. “hesperis noctu magis olet, inde nomine invento (Pliny) (Lewis & Short), the hesperis is more fragrant by night, thence the name was acquired.

Hesperides, gen. pl. Hesperidum (pl.f.III), “the Hesperides, daughters of Hesperus, or of Erebus and Nox, who, on an island beyond Mount Atlas, watched a garden with golden apples” (Lewis & Short); “The guardians of the golden apples which were carried off by Hercules as one of his labors” (Glare).

Insulae Hesperidum [= gen.pl.], “islands of the Hesperides” “a group of islands in the Atlantic Ocean (Lewis & Short).