LICHENS OF SANTA CRUZ PENINSULA 347 



It may be readily distinguished from Alcctoria juhata by its 

 uniform reddish brown color, and by the greater length and 

 denser mattinfj of its thallus. 

 Alcctoria frcmontii Twck.. Syn. N. Am. Lich. i: 45. 1882. 



Suppl. I : 422. 1858-9. 



VI. Theloschistes Norman. 



Thallus foliaceous, fruticose, or only made up of squamules ; 

 usually closely appressed and expanded, but in some species 

 tufted and erect, or even pendulous ; color, orange or yellow, 

 occasionally pale gray or ash-color. Apothecia shield-like^ 

 usuall}'^ abundant, the disk always yellow or orange ; spores 

 ellipsoid and polar-bilocular, or simple ; colorless. 



This group is distinct from all others except the genus Pla- 

 codium, with which it has several points of resemblance but from 

 which it may generally be distinguished by the much greater 

 development of the thallus. 

 Theloschistes Norman, Con. Gen. Lich. i6. 1852. 



KEY TO THE SPECIES. 



a. Thallus fruticose ; erect, decumbent, or pendulous. 



I. Jlavicans^ 347- 

 aa. Thallus foliaceous. 



b. Spores polar-bilocular, 8. 



c. Thallus pale or bright yellow or orange ; more or less or- 

 bicular. 

 d. Lobes short, thick, crenate, often pruinose. 



2. parietiruis^ 34S. 

 dd. Lobes many cleft. 



e. Thallus small, effuse or stellate; more or less concealed 

 by the small, very abundant apothecia. 



3. poly carpus^ 348. 

 ee. Thallus with granulose, powdery margins; apothecia 



numerous, large 4. lychneus laciniosa^ 349' 



CO. Thallus minute or small, effuse, scattered. .5. raDiidosus^ 349' 

 bb. Spores simple or i -septate, 30 to 60 in the thekes. 



6. concolor^ 349- 



I. THELOSCHISTES FLAVICANS (Sw.) Norm. 

 Thallus tufted, elongated, erect and spreading, becoming 

 decumbent ; branches numerous, narrow to linear, more or less 

 twisted and pitted or channelled ; margins with numerous small. 



