Eo Gee Evans: TAXONOMIC STUDY OF DUMORTIERA 
Wiesnerella Schiffn. and now known as W. denudata (Mitt.) 
Steph. The remaining species have been the cause of much con- 
fusion from the taxonomic standpoint, and this is especially true 
of D. hirsuta, D. irrigua, D. nepalensis and D. trichocephala. 
To give some idea of this confusion it will be sufficient to quote 
from the writings of Schiffner and Stephani, two of the most 
prolific hepaticologists of Europe. 
Schiffner, in 1893 (9, p. 36), estimated the number of species 
of Dumortiera as six, without enumerating them by name. He 
suggested, however, that they might all be forms of D. hirsuta, 
to which he attributed a range extending throughout all tropical 
countries. Under D. hirsuta he included the var. irrigua, a plant 
of Ireland, the Pyrenees, Italy and the southern United States. 
In another paper (10, p. 275) published the same year, he listed 
the var. irrigua from Brazil. In 1899 (11, p. 387) he cited D. hir- 
suta somewhat doubtfully from Japan, the plants in question com- 
bining a densely papillose thallus with a bristly female receptacle. 
In 1900 (12, p. 25) he referred certain Javan specimens, which 
he had previously determined as D. hirsuta, to D. trichocephala, 
and stated that the true D. hirsuta, if it occurred in Java at all, 
must be much rarer than D. hirsuta. In 1902 (13, p. 274) he 
listed D. irrigua, this time as a species, from La Palma, one of the 
Canary Islands; and in 1909 (15, p. 482) he discussed the rhizoids 
of D. irrigua (in plants from Italy and Brazil) and of D. hirsuta 
(in plants from Java). He apparently now regards D. irrigua 
and D. hirsuta as distinct species and considers D. trichocephala 
a synonym of D. hirsuta. 
Stephani’s statements about the species in question leave an 
equally indefinite impression. In 1886 (ry, D..23:. IB, D604), 
he listed D. hirsuta from the African islands of San Thomé and 
Fernando Po; in 1888 (19, pp. 280, 300), from the West Indian 
islands of Hispaniola, Porto Rico and Dominica; in 1892 (20, 
p. 177), from Costa Rica; in 1895 (22, p- 304), from the African 
districts of Kamerun, Kilimanjaro and Usambara, and also from 
Queensland and northern New Zealand ;* in 1897 (23, p. 78; 
24, p. 842), from Japan and the Hawaiian Islands. In 1894 


* The New Zealand records seem to have been based on D. dilatata (see page 167, 
footnote); this species, for a time, was supposed to be a synonym of D- hirsuta. 
