He had to blow his nose because of the rheum from his cold.
Her allergies caused a rheum discharge from her eyes and nose that caused her to want to take allergy pills so she wouldn't sniffle all day.
When the development of parenchyma is such that it more than fills up the spaces between the veins, the margins become wavy, crisp or undulated, as in Rumex crispus and Rheum undulatum.
Upon the exposed mountain slopes a species of rhubarb (Rheum Ribes) is noticeable.
Rheum palmatum and Polygonum cuspidatum are Chinese herbs which have recently gained some attention in the mainstream medical world.