22 LICHEN FLORA OF THE UNITED STATES 



Proper exciple. The exciple which is an upward continuation of the hypothecium 

 and devoid of algal cells. 



Pruinose. Covered with a bloom or powdery secretion. 



Pseudocortex. A cortex devoid of cellular structure and commonly showing well- 

 defined or more or less gelatinized hyphae. 



Pustule. A pimple-like or blister-like elevation. 



Pyrenocarpic. See angiocarpic. 



Rhizoid. A slender filament, consisting of a bundle of hyphae, extending downward 

 from the lower side of the thallus and usually penetrating the substratum. 



Rimose. Having chinks' and cracks. 



Scyphiform. Cuplike, or forming a cup; said of some podetia. 



Sessile. As applied to an ascocarp, meaning attached to the substratum by the 

 central portion of the lower side. 



Soredium. A tangled mass of algal cells and hyphae which is able to grow into 

 a new thallus under favorable circumstances of environment. 



Spermagonium. A minute cavity more or less imbedded in the thallus and con- 

 taining the spermatia borne on sterigmata. 



Spermatium. One of the sporelike bodies contained in the spermagonia and sup- 

 posed by some lichenologists to be male reproductive bodies. 



Squamule. A small scale. 



Squamulose. Composed of or bearing squamules. 



Stipe. A stalk of an ascocarp, devoid of algal cells. 



Thalloid. Thallus-like, having the structure of the thallus. 



Thallus. The vegetative portion of any lichen, on which are borne the repro- 

 ductive areas or organs. 



Thecial. Occurring within the thecium (hymenium). 



Trichomatic. Pertaining to or like a hair. 



Turbinate. Top-shaped. 



Umbilicus. The single strong attaching organ of some lichen thalli, composed of 



a large number of closely united hyphae. 

 Uniseriate. Placed in a single row; applied to spore arrangement in the ascus. 

 Urceolate. Pitcher-shaped, or cup-shaped. 

 Verruca. A wartlike elevation of a lichen thallus. 

 Verrucose. Covered with verrucae. 





