(Editor's Note: This article was originally published on March 13, 2009. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
Narcissus is a widespread genus of Old World flowering bulbs, many of which are extremely fragrant. The species of narcissus named (maybe) from the myth of Narcissus is probably Narcissus poeticus or N. tazetta. These tender narcissi are native to the Mediterranean region, including Greece, the Levant and North Africa.
There are several different mythological versions of the origins of the narcissus. The oldest is from the Homeric Hymn to Demeter, the goddess of the fruitful earth. Unfortunately, the text seems to identify the narcissus with the hyacinth, which is another flower with complicated mythological origins.
In the tale, Demeter's daughter Persephone is gathering spring flowers, probably for garlands, when she is abducted by Hades, the lord of the underworld, who used the narcissus to lure the maiden to him.
 She was playing with the deep-bosomed daughters of Oceanus and gathering flowers over a soft meadow, roses and crocuses and beautiful violets, irises also and hyacinths and the narcissus, which Earth made to grow at the will of Zeus and to please the Host of Many, to be a snare for the bloom-like girl --  a marvellous, radiant flower. It was a thing of awe whether for deathless gods or mortal men to see: from its root grew a hundred blooms and it smelled most sweetly, so that all wide heaven above and the whole earth and the sea's salt swell laughed for joy.  And the girl was amazed and reached out with both hands to take the lovely toy; but the wide-pathed earth yawned there in the plain of Nysa, and the lord, Host of Many, with his immortal horses sprang out upon her. (Homeric Hymn to Demeter 2)
This description of multiple blooms and fragrance suggests the species N tazetta, from which the popular Paperwhite narcissus originated. But it could also be the hyacinth.
In ancient times, this tale was extremely well-known, as it was the central myth of the Eleusinian Mysteries where Persephone's annual descent and rebirth were celebrated. The poet Sophocles refers to it in his play Oedipus at Colonus (361-364):
And, fed on heavenly dew, the narcissus blooms day by day with its fair clusters; it is the ancient crown of the Great Goddesses (Demeter and Persephone).
Today, however, the version most people know is the much later story of the beautiful and vain young man named Narcissus, who died of love after seeing his own reflection in a pool, where the flower then bloomed.
There are several different versions of this story. The Greek historian Pausanias tells two, but he claims that he prefers the myth of Persephone to either of these.
In the territory of the Thespians is a place called Donacon (Reed-bed). Here is the spring of Narcissus. They say that Narcissus looked into this water, and not understanding that he saw his own reflection, unconsciously fell in love with himself, and died of love at the spring. But it is utter stupidity to imagine that a man old enough to fall in love was incapable of distinguishing a man from a man's reflection.
 There is another story about Narcissus, less popular indeed than the other, but not without some support. It is said that Narcissus had a twin sister; they were exactly alike in appearance, their hair was the same, they wore similar clothes, and went hunting together. The story goes on that Narcissus fell in love with his sister, and when the girl died, would go to the spring, knowing that it was his reflection that he saw, but in spite of this knowledge finding some relief for his love in imagining that he saw, not his own reflection, but the likeness of his sister. (Description of Greece, 31, 7-8)
Better-known today is the version of the Roman Ovid. In this tale, Narcissus is loved by a nymph named Echo, but he spurns her affections. Echo calls out for revenge, and her cry is heard by Nemesis, who grants her wish. When Narcissus stops to drink at a pool, he falls in love with his reflection and dies of unrequited love.
But when they sought his body, they found nothing,
Only a flower with a yellow center
Surrounded with white petals.(Metamorphoses 3, 508-510)
Recently discovered manuscripts contain a poem that tells yet a different version, in which Narcissus spurns the love of another young man.
"In this story, Ameinias, a young man, loved Narcissus but was scorned. As a way of rebuffing Ameinias, Narcissus gave him a sword, which Ameinias used to kill himself on Narcissus' doorstep; he prayed to Nemesis that Narcissus would one day know the pain of unrequited love. This curse was fulfilled when Narcissus became entranced by his own reflection in a pool. Completing the symmetry of the tale, overcome by repentance, Narcissus took his sword and killed himself."1
There is, however, a more mundane explanation for the origin of the Narcissus name. As the naturalist Pliny wrote,
Two varieties of the narcissus are employed in medicine, the one with a purple flower, and the herbaceous narcissus. This last is injurious to the stomach, and hence it is that it acts both as an emetic and as a purgative: it is prejudicial, also, to the sinews, and produces dull, heavy pains in the head: hence it is that it has received its name, from "narce," and not from the youth Narcissus, mentioned in fable. (Natural History, Book XXI, Ch 75)
"Narce," or "narke" in Greek, is of course the root of "narcotic." It is defined as "numbness, deadness, or torpor." And in fact the Greek dictionary agrees with Pliny and derives the word narcissus from the "narke" root. The plant was said in antiquity to be sacred to Hades, and it was sometimes planted on graves. In short, the narcissus is a flower of death.
This information should not come as a surprise to gardeners. Narcissus is known to be toxic if consumed, particularly the bulbs. The plant contains alkaloids, most notably lycorine. This is often considered an advantage by gardeners, as the bulbs are less likely to be destroyed by pests such as rabbits.
Unfortunately, this mundane explanation leaves us without the myths. But this shouldn't be a problem. We can imagine our own versions.
Perhaps a young man, walking through a field of fragrant flowers, is overcome by their narcotic odor. He falls unconscious and dies, and the gods name him Narcissus after the flowers of death.
After all, if Ovid can make up his own versions of the myth, so can we.
Narcissus poeticus: Plantfiles, thanks to saya
Narcissus tazetta: Plantfiles, thanks to JamesCO
The painting of Narcissus is by Caravaggio