「Central part of a plant」is often the FLOWER, where one's eye is drawn to look, and is the most BEAUTIFUL part of most plants (central here refers to the principal or most important parts, not the physical center of the plant). Note that while being beautiful, the actual function of a FLOWER is for sexual reproduction among pistil (female) and stamen (male) parts of neighboring plants, forming seeds after being fertilized, and the meaning of the lower element is「spreading to access the central, sexual parts…」Which is exactly what a flower is, the「spread open sexual parts of a plant.」
Formerly meaning special types of FLOWERS, those destined for the emperor's garden of flowers, otherwise known as the royal harem of the finest concubines—but naturally a highly competitive and jealous place requiring bravery and spunk to succeed. Ascribed meanings of INTELLIGENT, TALENTED, GIFTED, SUPERIOR, EXCEPTIONALLY BEAUTIFUL, etc., are attributes of human beings generally, and not literal flowers per se—real flowers don't move too much voluntarily and therefore exhibit neither talented skill nor gifted intelligence.
Lower element indicates an inspection of a girl's virginity, the central requirement of the Chinese dragon emperor, involving the use of「two hands」on female sex organs to gently「pull open」the「vulva between spread legs」revealing the central parts for confirming the presence of an intact and undisturbed hymen of a girl picked by trusted vassals while「gathering flowers for the emperor's garden」(貴) for deflowering by the Dragon Emperor hisself [sic].
The hymen of a young girl is relatively TRANSLUCENT (apparently), being a membrane that covers the vaginal orifice and so a closer inspection was often necessary. Geishas still today auction their virginity, often for hundreds of thousands worth of U.S. dollars in an equivalent currency.
No suggestions are offered as to why this glyph's meaning is also the ENGLISH people and language, since of course the Chinese would never have thought to refer to the Brits as「gentle and inexperienced prepubescent virgin pussies.」…oh no, not ever.
「Among all living organisms, flowers, which are the reproductive structures of angiosperms, are the most varied physically and show a correspondingly great diversity in methods of reproduction.」
[ https://en.wikipedia.org/wiki/Plant_reproductive_morphology#cite_note-Barr02-1 2018-03-05 ]

External source definitions …excluding politically incorrect concepts and other meanings deemed offensive today; may include extended definitions, euphemisms, and mnemonics)
Chinese: brave; United Kingdom; British; England; English; abbr. for 英國|英国
Japanese EDRDG: England, English
Unihan extended: petal, flower, leaf; brave, a hero; England, English

Used within names (nanori)
あ　･　あい　･　え　･　すぐる　･　はな　･　ひ　･　ひで　･　よし　･　ら