How to Tell the Difference Between Lilies and Daylilies

Red daylilies
Red daylilies. Zelma Brezinska / EyeEm / Getty Images

The common names of flowers can be one of the more appealing and colorful aspects of gardening, but they can also be confusing. One man’s trout lily is another man's dog's tooth violet. We would all hate to lose the sentimental charm of common plant names, but there are times when it helps to know the Latin or botanical name as well. One of those times is when trying to tell the difference between true lilies (Lilium) and Daylilies (Hemerocallis).

While Liliums are pretty much always called lilies, many of us casually refer to daylilies simply as lilies, too. For the most part, who cares? However, if you are looking for a particular plant, or if you’re researching how to grow the plant you have, or perhaps you are wondering why your lilies die when you cut them to bring inside, you will need to be able to tell the difference between lilies and daylilies. Fortunately, it’s easy to distinguish the two plants apart by looking at the leaves, flower stems and how they grow.

Spotting a Daylily (Hemerocallis)

The leaves are a dead giveaway as to which plant you have. Daylilies have long, flat strap-shaped blades that grow in clumps from the crown of the plant, at the soil line. Daylilies grow from about one foot high up to four feet tall.

Daylilies also grow from thick, tuberous roots that are easily divided.

Daylilies are popular with hybridizers, and there are over 30,000 named varieties. Each flower blooms for only one day, which is why daylilies do not make good cut flowers. The name Hemerocallis comes from the Greek words "Hemera," which means day and "kallos", which means beauty. The flowers are borne on thin stalks, or scapes, that grow from the base of the plant. The scapes may be multi-branched.

Older varieties needed to be deadheaded every day, to keep them in bloom. Newer hybrids tend to deadhead themselves. Most plants have multiple buds that will bloom over a period of time.

If you look closely at the flower, you’ll see that six petals are in two layers of three. The top three are the actual petals. The bottom three are sepals. The center of the flower, the throat, is often a contrasting color. Each flower has either six or seven stamen and an additional two-lobed anther. Daylily flowers come in a variety of forms, including circular, triangular, double, ruffled, star-shaped and spider-shaped.

Spotting a Lily ( Lilium)

All true lilies are grown from a bulb of overlapping scales. There are about 100 species of lilies, but lilies are generally defined by their classification, such as Asiatic, Oriental, and Martagon (Turk’s cap). They have one central, unbranched stem that grows from the lily bulb, with the flower buds forming at the top of the stem. The leaves grow around the entire length of the stem, in whorls or spirals. Lilies can grow from about one and 1/2 feet tall to a towering 10 feet.

Lilies always have six petals and six anthers. Each bloom lasts a week or more. True lilies are popular cut flowers. The lowest buds on the stem will open first and the remaining buds will open sequentially through to the topmost buds. If you bring your lilies indoors, consider removing the anthers. The thick pollen can stain anything it falls on or touches.

Lilies flowers also come in a variety of forms, including trumpet-shaped, bowl-shaped, funnel-shaped and recurved. Here are some tips for growing true lilies.

While there are several differences between the two flowers, all you really need to look for is the growth habit of the stems and leaves. Multi-stems with strapping leaves coming from the base of the plant is always a daylily. A single stem with leaves whirling about it is always a true lily.

What’s a Tiger Lily?

There's a bit more confusion within the common names of lilies and that is the tiger lily. Tiger lily is a common name given to a true lily (Lilium) that has bright orange blossoms speckled with dark-brown spots, resembling a tiger's coloring. The blooms are orange or reddish orange and have dark-brown speckles covering the petals. The petals of the tiger lily curve backward and the whole blossom droops downward.

There is an orange daylily that has also naturalized along roadways. Many people refer to these daylilies as tiger lilies, but they weren’t the plant originally designated as the tiger lily. These orange roadsides lilies have their own, less flattering common name, ditch lilies.