The biological name for the daylily is Hemerocallis. The plant is called a fan,consisting of four main parts--the roots, the crown, the foliage (leaves), and the scape, which bears the flower. The roots are fibrous tubers that absorb water and minerals needed by the plant. The crown is the stem of the plant which joins the roots and leaves together. The leaves are long and grass-like with a rib on the underside. The leaves form fans and in time the plant multiplies and produces more fans which can be separated into two or more plants. The scape is the stalk that bears the flower. Scapes can be single leafless stalks or have two or three branches. Sometimes the scape may have a "bract" at the junction of the branch, where another small plantlet may grow. This small plantlet is called a "proliferation".
The daylily flower comes in many color patterns, flower forms, and sizes. The bloom lasts for only a day, hence its botanical name "Hemerocallis" which is derived from the Greek language and translates to "beauty for a day." Each plant may have many scapes, and in turn each scape may have many buds, which is referred to as a "high budcount." The flowering period for a plant can last from two to three weeks with some varieties flowering more than once. These plants are referred to as "reblooms".
The bloom season for daylilies are the months of March through December, with the peak bloom season in the Tallahassee area around the last week of May. Some varieties bloom early, starting in April. Others do not start blooming until late May or early June. Many daylilies have a flush of bloom and then don't bloom again until the following year. Others are recurrent or have repeat bloom cycles, sending up a flush of scapes, blooming out, resting two or three weeks, and sending up another flush of scapes. Then others seem to never stop blooming, sending up a new scape just as old ones bloom out.
The plant is introduced and registered by the hybridizer, who cross-pollinated it to form the seed for the new daylily. The hybrdizer is allowed to choose the name, but it must be accepted by the National Registrar of the American Hemerocallis Sociatey. There are over 35,000 named varieties of daylilies and perhaps another 100,000 seedlings.
Daylilies fall into two basic categories,dormant and evergreen, with intermediate points between: Dormant--Semi-dormant--Semi-evergreen--Evergreen. Evergreen daylilies thrive in North Florida and their foliage remains green during the winter months. In spring, if the tips of the foliage show signs of frostbite, it is a good idea to cut off this old foliage. The foliage of dormant daylilies dies back to the ground in winter and sometimes in the extreme heat of summer. Dormant daylilies do not grow very well farther south. In selecting dormant daylilies, many people rely on the experience of their friends or fellow daylily club members before purchasing expensive varieties. Dormant daylilies will perform better in north Florida if planted in partially shaded locations with wetter, cooler ground temperatures. The advantage in growing some dormant daylilies is that they start blooming later in the season, after many evergreen varieties have bloomed and are "resting" before rebloom.
All daylilies can be further identified into either tetraploid (44 chromosomes) or diploid (22 chromosomes.) If you are interested in flowers only, forget the last sentence, but if you are interested in hybridizing, you can only cross like (same quantity) chromosome counts.