Primrose is a group of small flowering plants from the Northern Hemisphere that bloom in early spring. They are native to England, the Alps, the Himalayas and China. The cave primrose is found in the southeastern corner of Utah and in northern Arizona. The botanical name for primrose is primula.
Primula or First Rose
A common characteristic among the primroses are their early blooming. The "prim" in the name comes from the Latin prima, which means first. One meaning given to primrose or primula is first rose of the year: prima rosa. Diana Wells, author of "100 Flowers and How They Got Their Name," calls the primrose the flower of first love.
"I Can't Live Without You"
Traditionally, a primrose means "I can't live without you." A primrose gift will tell your significant other, "I am yours forever." The ultimate in romantic gifts, a primrose shows your enduring love.
Evening Primrose is Not a Primrose
The evening primrose is not a primula but an oenothera. It blooms in summer and has more upright habit. It has yellow flowers that bloom only at night. While the primrose suggests enduring love, the evening primrose signifies inconstancy.
Source: http://www.ehow.com/facts_6776327_primrose-flower-meaning.html