It is very hygroscopic, absorbing water with the evolution of hydrochloric acid.
Hardy in 1875 (Ber., 8, p. 1594), and is a crystalline, very hygroscopic solid.
Potassium phenolate, C 6 H 5 OK, crystallizes in fine needles, is very hygroscopic and oxidizes rapidly on exposure.
The spores differ from those of ferns in their outer coat (exospore) being split up into four club-shaped hygroscopic threads (elaters) which are curled when moist, but become straightened when dry.
The root is made to press its way into the darker cracks and crannies of the soil, so bringing its root-hairs into better contact with the particles round which the hygroscopic water hangs.