436 BOTANICAL GAZETTE . [yuNE 
dichotomous, divaricate (max. length 12 cm.); secondary branches 
dichotomous, divaricate, furcate. A pothecia lateral, subpedicellate 
(max. diameter 6 mm.), disk chestnut, emarginate. Spores 5-7 
X3-5-4-5 #. : 
CONTINGENT PHASES: (a) more or less completely sorediate 
(E. p. soredifera Ach. Lich. Univ. 443. 1810). 
SupstRaATA: Trees, dead wood, fences, roofs, and occasionally on rocks. 
EOGRAPHICAL DISTRIBUTION: This species is confined in North America 
to the Pacific coast. I have examined specimens from the San Gabriel Mts., 
Cal., northward to British Columbia. Its variety is the plant found through- 
out the rest of our area. 
OBSERVATIONS: This lichen with its variety shows a common tendency 
(see Usnea) to vary from virescent on the Atlantic coast to stramineous on the 
acific. Specimens from the southwest have an inclination to expand their 
laciniae and to become channeled below, suggesting furfuracea. The apices 
are also more truncate and furcate; in fact the plants are comparable with 
the temperate European specimens which represent true prunastri; but both 
in Europe and throughout our area intergradation is shown, diverging type 
of laciniae occurring rarely in a single plant. Specimens from east of the © 
Rocky Mountains and from Alaska are of the linear type, and were referred 
by Wittey to E. thamnodes Nyl.9 To settle upon the rightful name foc 
linear plant is most perplexing. It appears, however, as follows: The oldest 
traceable name that has been used is arenaria Retz., but the type of Lichen 
arenarius Retz.” has been kindly sent me by Professor OrTo R. HOLMBERG 
of Lund, and proves to be Evernia divaricata (L.) Ach. as cited by ACHARIUS, 
and not as by Fries and NyLANDER as a variety under E. prunasirt. bed 
next possible cognomen used was given by ACHARIUS y 87 acilis (Lc. 442); 
with the locality “Sveciac.” In his herbarium, however, WAINIO™ eet 
two specimens, one from “Helvetia” and one from “Kamtschatka.’ The 
former he says has “laciniis laevissimis” and seems a young form of peer 
to which, he writes, Acwartus’ second description (Obs-) without dov 
refers. The latter specimen he says intermixed with it is Z. mesomor, 3 
Nyl. In the Acharian herbarium today (fide ELFVING) only the Kamtscha 
has not been 
used the words “laciniis laevissimis”: that the Swedish plant 
: lost, was 
ass 0 
found in the herbarium; and that the one specimen, apparently 
“‘laevissimis,” a character in no way fitting our variety, we must . very 
the next available name. This we find was given by FLoTOW (l.c.) in @ 
* FLorow, Lich. Schles. no. 54 c. 1829; and KorrBeER, Syst. Lich. Germ. o 
% Fl. Scand. Ed. 2. 292. 1795. 
™ Meddel. Soc. Faun. et Fl. 8:117. 1881. 
