From a botanical perspective, the term "Narcissus" refers to a genus (Narcissus) within the Amaryllidaceae family. The incredible diversity of flower forms observed in horticulture arises from natural variation and selective breeding within this genus, primarily involving species and their hybrids. The key structure that defines these forms is the corona, often called the trumpet or cup. This is not a separate set of petals but a tubular extension of the floral receptacle. Its size, shape, and proportion to the perianth segments (the outer six tepals, which are petal-like structures) are the primary botanical characteristics used for classification by organizations like the Royal Horticultural Society (RHS).
The corona is the most evolutionarily significant part of the Narcissus flower. Its primary biological function is to attract pollinators and guide them to the reproductive organs located at its base. The length, width, and reflexion of the corona directly influence the flower's overall morphology. A long, tubular corona creates the classic "trumpet" shape, while a very short, shallow corona results in a form where the colorful tepals are the most prominent feature. The corona's edge can be entire, frilled, or even contorted, adding another layer of distinction. The pigments within the corona often differ from those in the tepals, creating striking bi-color contrasts that are a result of specialized cell development.
Botanically, narcissus forms are categorized into divisions. Division 1, the Trumpet Daffodils, features a corona that is as long as or longer than the perianth segments. This form is efficient at protecting the nectar and anthers from rain. Division 2, Large-Cupped, exhibits a corona that is more than one-third but less than equal to the length of the perianth segments. This form offers a wide landing platform for pollinators. Division 3, Small-Cupped, has a corona not more than one-third the length of the perianth, making the star-shaped perianth the dominant visual element.
Further divisions highlight more specialized botanical mutations. Division 4, the Double Daffodils, is a result of a homeotic mutation where stamens are transformed into additional tepaloid structures. This creates a flower filled with multiple layers of petal-like organs, often obscuring the true corona entirely. While visually striking, this form can sometimes be less accessible to pollinators. Division 5, the Triandrus Daffodils, derives its characteristic nodding habit and reflexed perianth segments directly from its parent species, Narcissus triandrus. This pendulous form is an adaptation that may protect pollen from weather.
Beyond the hybrid garden forms, the true botanical species display a fascinating array of structures adapted to their native habitats. The Hoop Petticoat daffodil (Narcissus bulbocodium) has a vastly exaggerated, funnel-shaped corona and tiny, almost insignificant perianth segments—an extreme adaptation to attract specific pollinators. Conversely, the delicate Angel's Tears (Narcissus triandrus) displays multiple small, nodding flowers per stem with a very open, shallow cup. These wild forms represent the raw genetic material from which all the cultivated diversity has been selected, each with a unique floral architecture shaped by millennia of evolution.
