Basically, a Daffodil is a bulbous plant which produces flowers in the Spring. As with all things, there are exceptions and many variations. Some daffodils flower in the Autumn, some in winter. No Daffodils flower in the summer. That is hibernation time - or dormancy.
The correct botanical term for a Daffodil is Narcissus - or Narcissi in the plural. This sometimes causes confusion, in that some people will call certain types of Daffodils, Narcissus and visa versa!
Almost universally, the daffodils that we see - and maybe know - in the Spring are various shades of yellow. These are generally called daffodils - even by pedantic gardeners - mostly.
The term Narcissus is generally used for the species Daffodils - of which more later.
Most will agree that the famous 'Daffodils' poem by William Worsdworth, would not have gained such acclaim had it been .....
"I wandered lonely as a cloud
That floats on high o'er vales and hills,
When all at once I saw a crowd,
A host, of golden Narcissi
Beside the lake, beneath the trees,
Fluttering and dancing in the breeze."
(And not only for the fact that 'Narcissi' does not rhyme with 'hills'!)
Daffodils are part of the Amaryllidaceae family - the same as Amaryllis, Nerines and Hippeastrum - all sharing the same vital characteristic than joins them together as a group. They all have Trumpet-like flowers - similar to the picture on the left.
Some have double flowers - you can be forgiven for not seeing the Trumpet. Sometimes totally distorted - resembling a badly scrambled egg - but nonetheless popular amongst some!
Other Daffodils have shallow trumpets - which are normally referred to as 'cups'. This is when we start to get into the 'Narcissus' area. All explained later
The main vital statistic that all Daffodils have, is that they are all grown from bulbs.
All Daffodils are Narcissus, but not all Narcissus are Daffodils! An analogy could be that 'all fox terriers are dogs, but all dogs are not fox terriers'!
The term Daffodil is normally used for those large, trumpeted, flowering bulbs that we all adore in the Spring. These - whether the common yellow, golds, whites, bicolors or even double flowered - are all generally what we call Daffodils. this is the same if the daffodil has a single flower per stem or 6-8 flowers per stem. The term Daffodils can also cover many of the dwarf types. It is a collective common name for those bulbs - for all except the pedantic 'specialist' or snobby gardener!
The 'proper' or botanical name for all Daffodils is Narcissus. The same as the proper/botanical name for the Rose is 'Rosa', or the potato is 'Solanum'!
Most garden centres and bulb suppliers will call Daffodils, Daffodils, but just a few will maybe call them Narcissus. (On the same basis, they should be calling us - you and me - Homo sapiens!)
Where Narcissus comes into its own, and is normally used by bulb nurseries and growers, is when referring to the 'uncommon' species and hybrids, which are more collector or specialists items. Then you will see names such as Narcissus cyclamineus, and Narcissus bulbocodium.
So, for general everyday use, and for the common garden bulbs that we buy and plant by the bucketful - if you don't you should - Daffodils are fine. If you are going to join a horticultural society, then you better get used to calling them Narcissus!
The bulb of the daffodil is quite a complex self-contained plant - as are the bulbs we know as onions, shallots, and garlic. This bulb is their 'gateway' to being a perennial - a hardy one at that in most cases. daffodils are 'herbaceous' perennials, This is to say that as a perennial they will grow for many years, in keeping with many plants that we know as perennials, Daffodils die down and hibernate, or become dormant every year. Whilst perennial plants that we know tend to grow and flower in the summer, then die down for the winter, the daffodil is different. It flowers late winter (generally) but then dies down for the Summer!
The bulb of the Daffodil has functions that are not always well understood, so often cause disappointment. Starting 'after' flowering each year (Spring) the foliage of the daffodil does its job in helping to provide the bulb with plenty of food, which it then stores and later in the summer, uses this food reserve to produce the flower bud inside the unseen bulb underground. So the Daffodil bulb is only 'dormant' in that we cannot see it - as its foliage has died down - but it is a hive of activity underground..
Inside the daffodil bulb - soon after the foliage has died down - the flower bud for next spring starts to form. By the time you buy your Daffodils in the late Summer, the bulbs will already have the flower inside the bulb - ready to start its upward journey through the soil in late Winter. In fact, the flower buds often start to emerge from the ground in late December or early January - depending upon the type of Daffodil.
When you purchase the bulbs late Summer, you can cut one in half from top of nose through to base, and carefully part the scales (the leaves) to reveal the small flower bud and stem within. Wear disposable gloves and wash afterwards - daffodils - unlike onions - have poisonous sap.
After planting the dormant Daffodil bulb in late Summer, activity starts right away underground. Within weeks, the base of the bulb will start sending out roots - both to anchor itself, and to prepare to start finding food. The anchorage aspect of the Daffodil bulb is because it has to exert a lot of pressure to get the foliage and stem above ground. For feeding, the roots play an important part in obtaining minerals and food from the soil - which the foliage will then utilise, modify, and send back to the base of the plant - The Daffodil Bulb.
Now, it should be quite apparent why it is important to leave to foliage to die down naturally after the Daffodil has flowered. No need to tie them neatly in bundles, for a few weeks later, they will have died down. Cut the leaves off and you interrupt the food chain, weaken the bulb and have 'blind' (Non-flowering) Daffodils the following Spring.
It should also have explained why it ids possible to grow Daffodil bulbs into flower - either in water glasses, or in bulb fibre (which has no food to speak of). The flower bulb has already been provided for you during the previous months before you bought it!
There is a dividing line that moves according to who you are talking with, or what bulb nursery you are buying from, in relation to the different divisions or types of Narcissus - Daffodils. As I am now talking of Specialist or botanical divisions, I will refer to them as Narcissus! This will prevent my email box being the receptacle of insults and the like!
There are another 8 or so divisions. We are now getting into the stage where we talk about Narcissus - or Daffodils!
So as we began; all Daffodils are Narcissus - but not all Narcissus are Daffodils!