"Paperwhites" refers to a type of narcissus, usually of the Tazetta group, native to the Mediterranean. They are hardy only in warm winter climates, but are popular for indoor culture. The distinctive odor, which some find unpleasant, is due to a biochemical called indole.
The scent of indole has been characterized as "musky," though some say its concentrated odor in paperwhite flowers smells like dirty socks or even cat urine. Indole is also present in the fragrance of jasmine, orange flowers and gardenias, plants renowned for their pleasant fragrances.
Other Indole Incidences
In addition to being a constituent of some flower oils, indole is present in coal tar and animal fecal matter. Indole-3-carbinol, an indole configuration found in cruciferous vegetables such as broccoli, also has antic-cancer properties and may be responsible for the strong taste and smell of the vegetables.
The most common paperwhite maintained indoors is the Israeli variety, Ziva. Other Israeli varieties, such as Galilee, are also on the market and may share Ziva's high level of indole.