Reunion Lily

The reunion lily, also known as mourn-me-not, death's ransom, soul star, phoenix lily, and several other names, is a rare flower with a white, star-like appearance. Its petals have golden tips, a brilliant white body, and one or more purple-black rays at the base. Its colouration and unique seven-point star shape are quite distinct, making it easily recognizable. Healthy reunion lilies have been known to sustain up to four or five flowers at a time, each blooming two to four years apart. However, if the lily loses all of its flowers, it will grow a new one the following year.
The reunion lily has no known uses beyond serving as a resurrection spell component, and only the flower itself can serve this purpose; no other part of the plant is consumed when used in this way. Not just any flower can be used, however, as the blooms' potency comes with time. Even revivify, the most basic of resurrection magics, requires a flower no younger than two years old. More powerful spells will require increasingly older flowers, making them exponentially harder to find, grow, or acquire.
The reunion lily is notorious for being extremely difficult to cultivate. Those rare few who do manage to breed it in captivity often find their flowers do not survive long enough to be useful. Growing flowers that last for even two or three years is the sign of a true master gardener. However, rumour has it that sprites and pixies grow entire gardens of thriving Reunion Lilies in the deepest reaches of the wilds.
Unlike many flowers, the blooms do not wilt and regrow each season, but remain open year-round. As a bloom grows, it gradually replaces petals and lengthens its stem, leaving a tight spiral striation on its stalk just below its base. One can then easily determine the age of a flower simply by counting the number of ridges in the spiral. So long as the flower remains intact, it can be used as a spell component either fresh or dried. They are therefore occasionally preserved for later use.