Myrtle is from the Greek myrtos — the evergreen shrub sacred to Aphrodite, goddess of love; bridal myrtle wreaths feature in classical and medieval wedding traditions. Myrtle Wilson — character in F. Scott Fitzgerald's The Great Gatsby (1925); George Wilson's wife and Tom Buchanan's mistress; played by Isla Fisher in Baz Luhrmann's 2013 adaptation; her death scene in the Valley of Ashes is one of the most-analyzed passages in American literature, anchoring the novel's critique of the American Dream. Myrtle Reed (1874-1911) — American author; Lavender and Old Lace (1902) was a bestseller.
Myrtle does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Myrtle reduce to 3, The Communicator. This is a traditional interpretive system, not a factual claim about the name.