The mature spores of the sea sands plant of the family Hespericaceae.
Dry and mature spores, in the form of powder, brown or light brown, extremely light, smooth feeling when twisted by hand. Put in the palm of the hand that is slipping from the fingers; scattered in water is floating on the water surface, gradually sink after heating; easy to burn on fire and burst and flash, do not leave ashes, to dry, yellow-brown, light and smooth, can float in water, no sediment impurities, burst when ignited is preferred.
Contains fatty oil. Also contains a water-soluble component of sea sands.
Sweet light, cold.