1. SUMMARY
The results of a comparative study of six species of Pythium pathogenic to wheat seedlings are
presented. P. arrhenomnes, P. volutum, and P. tardicrescensn.sp., were found in both Canada
and England; or, for P. graminicolum and P. torulosum [?] in England and not in Canada; and P.
aristosporum. n.sp., only in Canada. The English forms were obtained from Bucks, Cambs,
Kent, Herts, Berks, and Lincs, and the Canadian forms from Saskatchewan. The similarity of the
English form considered as a geographic strain of P. torulosum with the form reported on wheat
in Italy by Petri is pointed out. Attention is drawn to the wide geographic distribution of species
of Pythium on graminaceous hosts. By the method of isolation used, it was relatively easy to
obtain one or more of these fungi either from wheat seedlings grown in potted soil collected at
random from virtually any field with cereals in the rotation, or from seedlings collected from the
poorer looking parts of such fields. All of the parasitic species isolated belong to the group of the
genus with lobulate sporangia. It is suggested that the many sphaerosporangial forms
encountered may render the wheat seedlings more liable to attack by the pathogenic forms
themselves. The use of fertilizers may prove beneficial.
Submit ophioglossum
Ophioglossum
Ophio·glos·sum
noun
Definition of OPHIOGLOSSUM
: the type genus of the family Ophioglossaceae comprising the adder's-tongues and having a solitary
simple frond with netted venation and a terminal spike formed of two rows of coalescent sporangia
Origin of OPHIOGLOSSUM
NL, fr.ophi- + -glossum,fr.Gkglōssa tongue — more at GLOSS (explanation)
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