R. HEBER HoweE, JR.: NOMENCLATURE OF GENUS USNEA 377 
two alternatives, the first plainly defying Linné’s intention, i. e., 
to use articulata as a synonym of barbata, turning to Acharius’s 
name for the present plant, either exactly as he proposed it or as 
combined by Nylander. The other, to accept Linné’s descrip- 
tions of both Lichen barbatus and L. articulatus, which are diag- 
nostic and (except for the composite type conditions referred to) as 
Dillenius figured and understood them, for the two descriptions 
leave no doubt that Linné intended to indicate two different 
plants. This latter procedure is it seems clearly the proper one, 
soundly based and entirely satisfactory. 
Series: Leptinae 
Chondroid axis one fifth diameter of thalline filament (inter- 
nodal section). 
Usnea articulata (L.) Hoffm. I find in the Linnean herbarium 
one sheet labeled 72 barbatus by Linné, which represents the 
typical plant generally recognized as articulata (L.) Hoffm. As 
already shown Linné was describing another species, based entirely 
on Dillenius, when he named Lichen barbatus, as this specimen 
was not acquired until 1767, twenty-two years after he first de- 
scribed it. Linné’s description is diagnostic, and his type locality 
an added argument. 
Our North American Linnean species therefore stand as follows: 
Usnea florida (L.) Web. 
plicata (L.) Web. = U. ceratina Schaer. non Ach. 
barbata (L.) Web. = U. plicata var. dasypoga Ach. 
Usnea articulata (L.) Hoftm. 
One cannot emend and adopt the Acharian name implexa for 
the plant known as U. dasypoga var. plicata (Hoffm.) Hue, a 
name absolutely untenable as preoccupied by a recognizable 
plant, as Acharius himself finally made it a synonym of his own 
plicata. Again, as I have said, Hoffmann referred to the same 
Dillenian plate (I. 12, f. 1) as Linné did, and the plant so named 
in the Hoffmann herbarium is curiously enough florida of Fries. 
One must therefore turn to Schaerer and adopt his variety stricta* 
* Orig. desc. “ramis simplicissimis, stricta’? Spicil. 507. 1840; “‘straminea, 
em, flaccida, pendula, tenera, ramis simplicibus, strictis, efibrillosis.” 
ype loc. “‘sylvy. alpin. Helvetiae.” Enum. crit. Lich. Europ. 4. 1850. Latin 
Strictus = = straight. 
