Cambridge (England), St. John's College, Main Gate, detail. Arms of St. John's College, Cambridge, being arms of the foundress Lady Margaret Beaufort, with Beaufort Yale supporters. With emblems of tiny flowers of the (white) Marguerite (daisy, Leucanthemum vulgare) and the (blue) Forget-me-Not (Myosotis sylvatica), a reference to the heraldic motto of Lady Margaret Beaufort Souvent me Souvient ("I often remember"). (Source: Beaufort Society's website (Google's cache of https://johnian.joh.cam.ac.uk/Beaufort-Society. It is a snapshot of the page as it appeared on 7 Dec 2020 03:27:08 GMT). Also visible is the Beaufort Portcullis heraldic badge. The forget-me-not flower was however used earlier as the heraldic badge of King Henry IV, legitimate son and heir of John of Gaunt, the illegitimate (later legitimised) issue of the latter becoming the House of Beaufort. One of Henry IV's mottos was souveyne vous de moi, the French name for the forget-me-not flower. Text from "The Lancastrian Esses Collar (Appendix 7)" erenow.net [1]:

As anyone who has looked at Henry IV’s accounts will be aware, the vernacular phrase most frequently found among the Latin entries is ‘souveyne vous de moi’. This can be translated as ‘remember me’ but it also can be read as the name of the forget-me-not flower. It appears in at least a dozen entries in Henry’s accounts between 1391 and 1398. For instance, his goldsmith’s account for 1391–2 records a payment for a wide belt for Henry ‘made in the form of a trail of soveigne vous de moy hanging copiously with gilded silver leaves and fronds’. In the embroidery section of the same account we may read of ‘a mantle and short loose gown for the lord of velvet motlee with St John’s Wort and soveyne vous de moy’. There are later references on this same folio to hundreds of gilded silver ‘leaves of soveigne vous de moy’. These relate to pictorial representations of flowers. Several entries in later accounts make this explicit; for example, ‘for mending a collar of the lord in the form of flowers of souveyne vous de moi … with a swan newly enamelled’, and ‘for a collar of esses and flowers of souveyne vous de moys’