From a botanical perspective, the most accurate starting point is the genus Narcissus. This is the scientific name for a group of perennial plants in the Amaryllidaceae (amaryllis) family. All plants commonly referred to as daffodils and jonquils belong to this genus. Therefore, the primary relationship is that "daffodil" and "jonquil" are common names for specific types of plants within the larger Narcissus genus. There are between 40 and 200 different species (depending on the classification system) and tens of thousands of registered cultivars. So, in strict botanical terms, every daffodil is a Narcissus, and every jonquil is a Narcissus, but not every Narcissus is a daffodil or a jonquil.
The term "daffodil" is the common English name for the entire genus. However, in horticultural and common usage, it often carries a more specific connotation. Typically, when someone says "daffodil," they are referring to the larger-flowered, often trumpet-shaped varieties of Narcissus. The classic example is the Narcissus pseudonarcissus and its cultivars, which feature a single large flower per stem with a long, central corona (the "trumpet" or "cup") that is noticeably longer than the surrounding petal-like tepals. They usually have flat, strap-shaped, blue-green leaves. The American Daffodil Society and the Royal Horticultural Society use a detailed classification system based on the form of the flower (e.g., trumpet, large-cupped, small-cupped, double), but all these classes fall under the broad, colloquial umbrella of "daffodil."
Jonquil refers specifically to certain species within the genus and their hybrids, most notably Narcissus jonquilla and its cultivars. Botanically, jonquils have distinct characteristics that set them apart from the general idea of a daffodil. They are known for their clusters of several small, fragrant flowers (2-6 per stem) with a small, cup-shaped corona. Their foliage is a key identifier: jonquils have dark green, cylindrical, rush-like leaves (similar to chives) rather than the flat, strap-like leaves of most other daffodils. They also tend to have a more delicate appearance and are celebrated for their strong, sweet perfume. Jonquils are often among the later-blooming types in the Narcissus family.
The confusion arises because the common names are used interchangeably in casual conversation, but the botanical distinctions are clear. The term "Narcissus" is the only technically correct term for the entire group. "Daffodil" is the common name for the genus but is often applied to the larger, trumpet-shaped varieties. "Jonquil" is a specific botanical division referring to a section of the genus defined by multi-flowered stems, fragrant blooms, and hollow, rush-like foliage. To summarize the key differences: a large, solitary flower with a flat leaf is almost certainly a daffodil. A cluster of fragrant flowers on a single stem with a round, hollow leaf is a jonquil. And both are, unequivocally, Narcissus.
