107 
67. COLLAR-ROT FUSARIUM. 
(Fusarvum limonis , Briosi.) 
Pustules gregarious, confluent, pale-straw colour, or forming 
effused slimy masses at margin of rotting collar. Hyphm 
hyaline, flexuous, spreading, septate, branched, elongated, narrow, 
li— 2f.i. broad. 
Conidiophorcs erect or ascending, branched alternately, 
opposite, or only on one side, bearing conidia at summit. 
Conidia fusiform, crescent-shaped or straight, acute at each 
end or blunt, usually 3-scptate, very slightly constricted at 
septa, sometimes aseptate, 1—2 or 4-5 septate, variable in size, 
22-45 X 2-4p., average about 30 x 3 g. 
At the collar of Orange and Lemon stems and extending into the 
roots, producing the disease known as “ Collar-rot, 11 “ Foot-rot,” 
or “Mai di gonimn.” All the year round. Common in Victoria, 
also in New South Wales, Queensland, and South Australia. 
Specimen from Doncaster. 28th August, 1896. Recorded for 
the first time in Australia. 
The Sweet Orange ( Citrus aurantium, , L. var. dulcis) and 
Lemon {Citrus medica , L. var. limonium) are specially liable to 
this disease, while the Sour or Seville Orange ( C . aurantium , L. 
var. bigaradia) and the Pomelo and Shaddock (C. aurantium,, L. 
var. decumana) are much more resistant than the Sweet Orange 
or the Lemon. 
The cause of this disease is still in dispute, but the contagious 
nature of it seems to point to some parasitic organism. Briosi, 
who first named and described the above fungus in Italy has 
always found it to accompany the disease, but it is difficult to say 
if it is the primary cause. He adds, however—“ I do not believe 
there can be any doubt that its presence accelerates the dis¬ 
organization of the tissues and aids in extending the disease.” 
I have also invariably found it penetrating the diseased tissues 
with its long slender wandering filaments. 
Numerous conidia were found in active germination, protruding 
filaments at either end or laterally from the segments. (Plates 
XL, XII., and Figs. 142, 143, 144, 145.) 
68. FLESHY FUSARIUM. 
(Fusarium sarcochroum , Sacc.) 
Sporodochia minute, coral pink, convex, orumpent, about £ mm. 
diam., or in widely effused patches more ruddy, even ferruginous in 
colour, and rupturing bark. 
Hyphfc pale pink collectively, densely fasciculate, septate, 
repeatedly dichotomously branched, 3)>-4^/i. broad. 
