128 



Mycologia 



Figures: [Dill. Hist. Muse. pi. 12. f. 7. 1841]. 



Diagnosis : Thallus pendulous, brown, primary branches sulci- 

 form, subterete, axils compressed. Apothecia concolorous or pale 

 brown. 



Description : Thallus pendulous, filamentous, pliant, subterete, 

 subtortulous, brown; cortex glabrous or dull, sulciform, rarely 

 ruptured with white soralia ; primary branches remotely dichoto- 

 mous, axils compressed (max. length 40 to 50 cm.) ; secondary 

 branches dichotomous slender, filiform; fibrils capillaceous. Apo- 

 thecia rare, small (max. diam. 2 mm.), convex, innate, margin 

 entire, disk dull, concolorous or pale yellowish. Spores 5-9 

 X 4-7^- 



Contingent phases: (a) Cinereous or partially cinereous 

 (Alectoria jubata cana Ach. 1. c. 593). 



Substrata: On living and dead coniferous and deciduous trees, 

 more common on the former. 



Geographical distribution : This plant is not typically repre- 

 sented in North America, but is largely replaced in the west by 

 the closely allied species Fremontii. 



Observations: As was in the case of the genus Usnea, jubata 

 like barbata has come to have a sectional rather than a specific 

 concept, and the varieties prolixa and implex a have included 

 jubata, or else jubata has stood for merely atypical specimens of 

 the varieties. Stizenberger* dropped jubata altogether, beginning 

 his nomenclature from Acharius, but as jubata seems to be un- 

 questionably a synonym of prolixa, and has priority, it must 

 stand. Prolixa (sulciform) has never in this country (Macoun) 

 been seriously considered as a valid variety, and it is generally 

 known as a variety of jubata. Implexa has been given correctly 

 by American lichenologists to the slender, eastern specimens 

 whose length does not usually exceed 10 to 15 cm., while jubata 

 has been often wrongly reserved by careful workers for the 

 sterile examples of Fremontii. 



Tuckerman's diagnosis of jubata includes the entire range 

 from tufted conditions of the variety chalybeiformis to the pen- 

 dulous implexa, and also those pale specimens referable to the 

 variety sub cana. Below, under (b) and (c), he gives additional 



* See also Hue, Lich. extra-Europ. Nouv. Arch. Mus. d'hist. nat. i : (4). 

 86. 1899. 



