Dermatology is an intrinsically visual specialty, with pattern recognition a vital skill for clinical practice. It therefore follows that many of the classic descriptions of cutaneous pathologic abnormalities draw on parallels from the natural world, particularly the realm of botany. Trees, leaves, fruits, and flowers have all lent themselves to morphological descriptions over the centuries.
The distribution of the papulosquamous plaques of pityriasis rosea has been compared to a fir tree and the hair shaft changes of trichorrhexis nodosa to bamboo. The figurate polycyclic plaques of erythema gyratum repens have been described as resembling wood grain and the jagged forked lesions of livedo racemosa tree branches.1 The induration associated with scleroderma is classically described as woody, and the neurofibromas of neurofibromatosis are said to have a rubbery consistency. Lichenification derives its name from lichen (a composite organism of fungi and algae living symbiotically), and the tumors of mycosis fungoides were initially thought to be fungal growths (though strictly speaking, the kingdom of Fungi is separate from that of plants).
Sebaratnam DF. Apple of the Dermatologist’s Eye. JAMA Dermatol. 2014;150(12):1280. doi:10.1001/jamadermatol.2014.3086