358 
Joumal oj Agricultural Research 
Vol. XXX, No. 4 
Banning, Fungi of Maryland (MS. in 
Herbarium N. Y. State Mus.), PI. 46. 
1889. (As Clitocybe aquatica.) 
Peck, Ann. Rpt. N. Y. State Mus. 51: 
PI. 51, Figs. 1 to 5. 1898. (As 
Clitocybe monadelpha.) 
Peck, Mem. N. Y. State Mus. 3: PL 46, 
Figs. 7 to 12. 1900. (As Clitocybe 
monadelpha.) 
Mcllvaine, Amer. Fungi, PI. 27. 1900. 
(As Clitocybe monadelpha.) In Plate 
16, Fig. 2, a poor illustration is given 
of Peck’s Armillaria mellea exannu- 
lata, which is reproduced by Wilcox, 
Okla. Agr. Exp. Sta. Bui. 49: PI. 4, 
Fig. 4. 1901. 
Bresadola, Fungi Trid. 2: PI. 197. (As 
Clitocybe tabescens.) 
Wilcox, Okla. Agr. Exp. Sta. Bui. 49: 
Pis. 1 to 3, 5, 7 to 9; Figs. 10, 11, 14 
to 16,19. 1901. (As Clitocybe para¬ 
sitica ) 
Boudier, Ic. Myc. 1: PI. 61 (51a). 
1905-10. (As Clitocybe tabescens.) 
Hard, Mushr., PI. 12 (fig. 75). 1908. 
(As Clitocybe monadelpha.) 
Duggar, Fungous Diseases of Plants, 
Fig. 234. 1909. (As Clitocybe para¬ 
sitica ) 
Rolland, Atlas, PI. 25. 1910. (As 
Clitocybe gymnopodia.) 
Coker and Beardslee, Jour. Elisha 
Mitchell Sci. Soc. 38: PI. 12; 33, 
Fig. 7. 1922. (As Clitocybe tabes¬ 
cens.) 
On his map in Plate 11, Wilcox (58) 
shows the localities in which occurs the 
rhizomorphic root rot described by him 
as found in Texas, Oklahoma, Missouri, 
Illinois, Indiana, Ohio, and Georgia, 
and adds that California and Oregon 
should have been marked as States 
from which the same disease had been 
reported. The rhizomorphic root rot 
reported by Wilcox from the two 
latter States, and assumed by him to 
be due to Clitocybe parasitica, was in 
all probability caused by Armillaria 
mellea, which the writer knows from 
personal observation is of widespread 
occurrence on the Pacific coast. So far 
as the writer’s information extends, 
there never has been an authentic re¬ 
port of Clitocybe root rot occurring on 
the Pacific coast or in the Pacific North¬ 
west. 
From the reports of Peck we know 
that the species of Clitocybe that we 
now call C. tabescens occurs as far 
north as New York on the Atlantic 
coast. Kauffman (22) reported the 
occurrence of Clitocybe monadelpha in 
Michigan, and Fawcett (16, p. Ixvi) re¬ 
ported Clitocybe parasitica as causing 
a root rot of peach in Florida. The 
cultures of Clitocybe root rot men¬ 
tioned above as furnished by Miss 
Richards were also from Florida, having 
been isolated from a rotted eucalyptus 
root. Since coming to Florida in 1923 
the writer has collected specimens of 
Clitocybe tabescens growing at the bases 
of stumps of Washingtonia robusta and 
Ilex opaca at Gainesville, and at the 
base of a living oak tree at Cocoa. He 
has also observed two instances of this 
fungus causing a root rot of guava 
(Psidium guajava), one at Cocoa and 
the other near Courtenay on Merritt’s 
Island. 8 
Murrill (28, p. 198) states that the 
species also occurs in Mexico and 
British Honduras. According to the 
taxonomic literature previously cited 
in this paper, the plant has a wide dis¬ 
tribution in Europe. Nowhere in the 
European literature, however, has the 
writer seen any mention of its causing 
a rhizomorphic root rot of woody 
plants. In fact, even the cultural 
characters of the European form appear 
to be unknown. 
In the United States the range of 
Clitocybe tabescens , which extends from 
New York south to Florida and west to 
Michigan, Kansas, and Texas, over¬ 
laps to a large extent the range of the 
closely related Armillaria mellea, which 
likewise causes a rhizomorphic root rot. 
Except for a few middle-eastern States, 
however, root rot caused by Clitocybe 
tabescens has been reported only from 
the southern part of the United States, 
where it is of most widespread occur¬ 
rence. 
RELATION OF CLITOCYBE ROOT 
ROT TO TIMBERED LANDS AND 
DRAINAGE 
The root rot of grapevines and fruit 
trees caused by Clitocybe tabescens is 
associated with lands which were 
formerly covered with hardwood tim¬ 
ber, especially oak. This disease ap¬ 
pears to be practically unknown in 
strictly prairie soils and in old land, 
except at the margins in close proximity 
to timbered land. Men who have had 
no experience with the disease on old 
land have found that it quickly made 
8 Thus far the writer has not found grapevines attacked by Clitocybe root rot in Florida, but has 
had virtually no opportunity to investigate this problem since coming to this State. In a case of 
root rot observed on a single Herbemont vine at Bartow the fungus associated with the root rot did 
not appear to be Clitocybe nor did the one isolated prove to be a rhizomorph-producing fungus. Al¬ 
though cultures have been maintained for several months, neither spores nor fruiting-bodies have 
been secured. 
