THE BRYOLOGIST 
Vol. XXV November, 1922 No. 6 
THE STATUS OF GYROWEISIA IN NORTH AMERICA 
A. LeRoy Andrews 
Gyroweisia has in fact no valid status anywhere. Limpricht^ complained of 
the several names that Schimper had at different times applied to this genus, but 
did not perhaps take the trouble to verify his references. Thus I have been un- 
able to find Weisiopsis published by Schimper as a genus, with priority, if Lim- 
pricht were right. Limpricht's source was presumably Schimper's own statement,^ 
but this speaks only of a subgenus Weisiopsis. In the Bryologia Europaea I 
find no such name either as genus or subgenus under plate 28 or in the text re- 
ferring to it, but only as a subgenus in the index of Vol. I, page VII, which is 
apparently from the later date of 1851. The case is different with Weisiodon, 
which was entirely adequately published as a genus^ and by all the rules of 
priority should supplant the later Gyroweisia. Its type-species was the Weisia 
reflexa of Bridel occurring in southern Europe and northern Africa. Schimper's 
reason for changing the name to Gyroweisia was the inclusion of the European 
Gymnostomum tenue of Schrader, which he rightly recognized to be closely re- 
lated to the other, but which has no peristome teeth. Both have a prominent 
persistent annulus — hence the name Gyroweisia, Weisiodon being no longer 
appropriate. But it should be obvious that a generic name need not be a generic 
description, cannot in fact remain one with the growth of knowledge of forms 
and their natural relationships.^ Priority demands the retention of Weisiodon, 
if the genus itself is worthy of retention. As a matter of fact, like many others, 
it is not particularly well understood. Engler & Prantl's Natiirliche Pflanzen- 
familien includes in it for the first time a number of exotic species, and their 
figure taken from a portion of the plate of Weisia reflexa in Bryologia Europaea 
has inspired still further additions. 
As to North America, the inclusion of this genus in its moss-flora rests in 
the first place upon number 21 of Drummond's Musci Americani named Gymno- 
1 Laubmoose 1, 235. 1886. 
2 Corollarium, 9. 1855. In the light of the facts here developed the genus Weisiopsis recently 
proposed by Brotherus (Finsk. Vetensk. Soc. Forhandl. 62: A: Nr. 9, 192 1, according to reference; 
1 have not seen the paper) would be valid so far as the name is concerned, but it seems questionable 
whether a name which has been the subject of controversy should be used again for a still different 
group. 
3 Corollarium, 9. 1855. 
4 Cf. The Bryologist, XXlll, 3of. 1920. 
The September number of The Bryologist was published November 7, 1922 
