Months

February:

February which means purification was added to the Roman calendar by Numa Pompilius about 713 BC.   February remained the last month of the calendar year until the time of the decemvirs (c. 450 BC), when it became the second month.   At certain intervals February was truncated to 23 or 24 days; and a 27-day intercalary month, Intercalaris, was inserted immediately after February to realign the year with the seasons.

Under the reforms that instituted the Julian calendar, Intercalaris was abolished, leap years occurred regularly every fourth year (after a few years of confusion), and in leap years February gained a 29th day.   Thereafter, it remained the second month of the calendar year, meaning the order that months are displayed (January, February, March, ..., December) within a year-at-a-glance calendar.   Even during the Middle Ages, when the numbered Anno Domini year began on March 25 or December 25, the second month was February whenever all twelve months were displayed in order.  The Gregorian calendar reforms made slight changes to the system for determining which years were leap years and thus contained a 29-day February.

Historical names for February include the Anglo-Saxon terms Solmonath (mud month) and Kale-monath (named for cabbage) as well as Charlemagne's designation Hornung.  In Finnish, the month is called helmikuu, meaning "month of the pearl"; when snow melts on tree branches, it forms droplets, and as these freeze again, they are like pearls of ice.  In Ukrainian, the month is called лютий meaning the month of ice or hard frost. 

The birthstone is traditionally the amethyst. 

The birth flower is traditionally the Violet. 

Violets (Viola) are a genus of flowering plants in the family Violaceae, with around 400-500 species throughout the world, mainly in the temperate Northern Hemisphere but also in Hawaii, Australia, and the Andes in South America.  They are typically found in moist and slightly shaded conditions such as hedgerows.

Flower colors vary in the genus; many are violet as their name suggests, and some are blue, some yellow, some white, some cream; some are bi colored, often blue and yellow.  Making beautiful colored Birth flowers for February.
One quirk of some violets is the elusive scent of their flowers; along with terpenes, a major component of the scent is a ketone compound called ionone, which temporarily desensitizes the receptors in the nose; sniff all you like, you won't get any more smell from the flower.  

Also the dog violets, a group of scentless species which are common violets in many areas, the Sweet Violet Viola odorata (named from its sweet scent), and many other species whose common name includes the word "violet". Several species are known as pansies, including the Yellow Pansy of the Pacific coasts.

Zodiac Symbol:  Aquarius

In astrology, Aquarius is considered a "masculine", positive (extrovert) sign. It is also considered an air sign and is one of four fixed signs.  Aquarius has been traditionally ruled by the planet Saturn, and, since its discovery, Uranus has been considered a modern ruler of this sign.

Aquarius - the Water Bearer

Aquarius has also been identified as the pourer of the waters that flooded the Earth in the ancient Greek version of the Great Flood myth. As such, the constellation Eridanus the river is sometimes identified as a river being poured by Aquarius.  Aquarius may also, together with the constellation Pegasus, be part of the origin of the myth of the Mares of Diomedes, which forms one of The Twelve Labours of Heracles.  Its association with pouring out rivers, and the nearby constellation of Capricornus, may be the source of the myth of the Augean stable, which forms another of the labours. 

There are a list of "National Month" observances associated with February but the one most often referred to is "Black History Month" and being the month in which St. Valentine's Day falls, it's also "National Wedding Month."