polyanthus
A type of primula, apparently originally from a hybrid between the cowslip and the primrose, having many different-coloured flowers.
[T]he Hens all want to sit, the Primroses Polyanthuses &c crowd the Hedges; & a Rose Tree or two are quite full of Leaves.
Where it comes from
From Renaissance Latin polyanthus, corresponding to poly- + Ancient Greek ἄνθος (ánthos, “flower”).
Adapted from the Wiktionary entry polyanthus (CC BY-SA 4.0).