THE LIFE HISTORY OF THE GRAPE ROOTROT FUNGUS 
ROESLERIA HYPOGAEA THUM. ET PASS . 1 
By Angie M. Beckwith 
Junior Pathologist> Fruit-Disease Investigations , Bureau of Plant Industry , United 
States Department of Agriculture 
INTRODUCTION 
The fungus Roesleria hypogaea, associated with a rootrot of grapes, has 
long been known, especially in the grape-growing regions of Europe. It 
has not been definitely proved that this fungus is lie primary cause of 
the rot, but there is no question that, once established, it contributes 
largely toward the killing of the roots. Disagreement among mycolo¬ 
gists as to the identity of some well-known fungus is often due to a lack 
of knowledge of its life history. Confusion has more than once arisen 
because of an accidental similarity of fruit bodies or spores. A case in 
point is that of Roesleria and Pilacre. 
We are indebted to Brefeld (5 2 ) for the beautiful illustrations of Pilacre 
petersii B. & C., a fungus which he believed to represent a very primitive 
Basidiomycete. His figures of the fruiting bodies on bark show a 
“ gleba” composed in part of short septate branches, each bearing a 
definite number of spores. Such a branch he considers a simple basidium. 
Roesleria hypogaea Thiim. and Pass., an ascogenous fungus whose fruiting 
bodies have a strong superficial resemblance to those of P . petersii , is, 
on this account, most interesting. Calicium pallidum Pers., well known 
to lichenologists, also has fruiting bodies similar in general appearance 
to those of Roesleria and P. petersii . Since Rehm (27, p. 396) con¬ 
siders Coniocybe pallida (Pers.) Fr. a synonym of R . hypogaea , and 
Bayliss-Elliott and Grove (8) suggest that R. hypogaea is merely the 
ascogenous stage of P. petersii , and since Viala and Pacottet (33) report 
conidial and chlamydosporic forms of Roesleria in culture, it is not sur¬ 
prising that we find the greatest confusion of these names in the 
literature. The writer has had the opportunity recently to study 
R. hypogaea and P. petersii in culture and has also compared them 
with specimens of the lichen, Coniocybe pallida , with the result that we 
find that there is no basis for considering these fungi identical or 
genetically related. 
From a review of the literature it will be seen that the grape rootrot 
fungus has been described under a number of different names and com¬ 
binations. The following list includes such as appear from original de¬ 
scriptions and illustrations to refer to a Discomycete identical with 
Roesleria hypogaea of von Thiimen and Passerini. 
Pilacre subterranea Wein. 1832. (36, p. 458.) 
Pilacre friesii Wein. (in Flora) 1832. (36, p. 438.) Not Wein. 1834. 
Onygena friesii Wein. 1834. (57, p . 413-414.) 
Vibrissea flavipes Rab. 1852. (26, p. 286.) 
Sphinctrina coremioides B. & Br. 1872. (2). 
Roesleria hypogaea Thiim. & Pass. 1877. (32.) 
1 Received for publication Nov. 23, 1923. 
* Reference is made by number (italic) to "literature cited, pp. 615-616.” 
(609) 
Journal of Agricultural Research, 
Washington, D. C. 
Vol. XXVII, No. 8 
Feb. 23, 1924 
Key No. G-355 
