Following on from yesterday’s hybrids, we have the word Grex. The word itself is from the Latin for flock or herd (gregis). Although grex refers to a number or population of individuals, if there is more than one grex they are grexes or gregis, abbreviated to gx. although why we need to abbreviate a four letter word with a three character abbreviation is beyond me.

Anyway, the word grex is usually applied to orchids though it is also used for rhododendrons. The word grex is applied to a group of hybrid individuals all from the same cross. An orchid pod can contain many thousands of seeds and produce many diverse individuals. Although when individuals are selected they are named and given cultivar names (in ” quotes) all these plants, which are like family members, also bear a grex name. So we get x Vuylstekearia Cambria ‘Plush’ (Cambria is the grex and ‘Plush’ is the cultivar – one of the many seedlings from a cross of the two parents which was selected for naming). This is one of the commonest orchids sold as pot plants. I am sure that the orchid above is
x Vuylstekearia and the grex is Cambria but I do not know the cultivar. The grex name is always written in ‘roman’ (not italicised) and with a capital letter.

In rhododendrons, the most famous is  the Rhododendron Loderi grex, produced at Leonardslee in Sussex by Sir Edmund Loder after 1901, hybrids between a particularly fragrant R. fortunei and R. griffithianum. They includes the huge pink Rhododendron Loderi ‘King George’ later blooming Loderi ‘Game Chick’ (above),  and even later  Loderi ‘Venus’.

grex, orchid, rhododendron loderi, Rhododendron Loderi 'King George', rhododendron loderi game chick, Vuylstekearia Cambria 'Plush'