E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Vert [green],
in heraldry, signifies love, joy, and abundance. It is represented on the shields of noblemen by the emerald, and on those of kings by the planet Venus
1
In heraldry vert is symbolically expressed by diagonal lines running from right to left of the shield. Lines running the reverse wayi.e. from left to rightmean purpure.
2
N.B. English heralds vary escutcheons by only seven colours, but foreign heralds employ nine colours. (See HERALDS.)