Narcissus is a genus of predominantly spring perennial plants of the amaryllis family, Amaryllidaceae. Various common names including daffodil, narcissus and jonquil are used to describe all or some members of the genus. Narcissus has conspicuous flowers with six petal-like tepals surmounted by a cup- or trumpet-shaped corona. The flowers are generally white or yellow (also orange or pink in garden varieties), with either uniform or contrasting coloured tepals and corona.
The pale brown-skinned ovoid tunicate bulbs have a membranous tunic and a corky stem (base or basal) plate from which arise the adventitious root hairs in a ring around the edge, which grow up to 40 mm in length. Above the stem plate is the storage organ consisting of bulb scales, surrounding the previous flower stalk and the terminal bud. The scales are of two types, true storage organs and the bases of the foliage leaves. These have a thicker tip and a scar from where the leaf lamina became detached. The innermost leaf scale is semicircular only partly enveloping the flower stalk (semisheathed).(see Hanks Fig 1.3). The bulb may contain a number of branched bulb units, each with two to three true scales and two to three leaf bases. Each bulb unit has a life of about four years.
The floral tube is formed by fusion of the basal segments of the tepals (proximally connate). Its shape is from an inverted cone (obconic) to funnel-shaped (funneliform) or cylindrical, and is surmounted by the more distal corona. Floral tubes can range from long and narrow in sections Apodanthi and Jonquilla to rudimentary (N. cavanillesii).
Most species have 12 ovules and 36 seeds, although some species such as N. bulbocodium have more, up to a maximum of 60. Seeds take five to six weeks to mature. The seeds of sections Jonquilla and Bulbocodium are wedge-shaped and matte black, while those of other sections are ovate and glossy black. A gust of wind or contact with a passing animal is sufficient to disperse the mature seeds.
The eventual position of Narcissus within the Amaryllidaceae family only became settled in this century with the advent of phylogenetic analysis and the Angiosperm Phylogeny Group system. Within Amaryllidaceae the genus Narcissus belongs to the Narcisseae tribe, one of 13 within the Amaryllidoideae subfamily. It is one of two sister clades corresponding to genera in the Narcisseae, being distinguished from Sternbergia by the presence of a paraperigonium, and is monophyletic.
Although the family Amaryllidaceae are predominantly tropical or subtropical as a whole, Narcissus occurs primarily in Mediterranean region, with a centre of diversity in the Iberian Peninsula (Spain and Portugal). A few species extend the range into southern France, Italy, the Balkans (N. poeticus, N. serotinus, N. tazetta), and the Eastern Mediterranean (N. serotinus) including Israel (N. tazetta). The occurrence of N. tazetta in western and central Asia, China and Japan are considered introductions, albeit ancient (see Eastern cultures). While the exact northern limit of the natural range is unknown, the occurrences of wild N. pseudonarcissus in Great Britain, middle and northern Europe are similarly considered ancient introductions.
Another fungus which attacks the bulbs, causing narcissus smoulder, is Botrytis narcissicola (Sclerotinia narcissicola) and other species of Botrytis, including Botrytis cinerea, particularly if improperly stored. Copper sulfate is used to combat the disease, and infected bulbs are burned. Blue mould rot of bulbs may be caused by infection with species of Penicillium, if they have become damaged either through mechanical injury or infestation by mites (see below). Species of Rhizopus (e.g. Rhizopus stolonifer, Rhizopus nigricans) cause bulb soft rot and Sclerotinia bulborum, black slime disease. A combination of both Peyronellaea curtisii (Stagonosporopsis curtisii) and Botrytis narcissicola causes neck rot in the bulbs.