IOWA ACADEMY OF SCIENCE 
151 
Hypocreaceae. 
27. Claviceps purpurea, Fr. 
Found on many different grasses, especially wild rye, cultivated rye, tim- 
othy and quack grass. Produces a disease known as ergotism. The fungus 
is very poisonous, causes dry gangrene and abortion. 
FUNGI IMPERFECT! : 
28. Oidium albicans, Robin. 
Commonly found in the mouth of sucking animals of different kinds, 
especially calves. 
29. Fusarium. Sp. 
Commonly found on moldy corn, causes derangement of the digestive or- 
gans and in some cases death. 
EMBRYOPHYTA ZOIDIOGAMA. 
Pteridophyta. 
FILICALES. 
POLYPODIACEAE. 
30. Pteris aquilina, L. 
The common brake is found in eastern and northeastern Iowa. Produces 
a large, strong root-stock. Said to be poisonous to cattle and horses. 
31. Aspidium marginale, L. 
Of rare occurrence in the state. The root-stock is used as a remedy for 
the expulsion of tapeworm and undoubtedly sometimes produces poisoning. 
OSMUNDACEAE. 
32. Osmunda claytoniana, L. 
This fern is widely distributed in eastern and northeastern Iowa, occurring 
as far west as the Des Moines basin. The odor is not pleasant and the plant 
is undoubtedly more or less poisonous. 
EQUISETALES. 
Equisetaceae. 
33. Equisetum arvense, L. 
The common horse-tail is supposed to be injurious to horses, so reported 
in Vermont by Dr. Richman and Professor Jones, and reports of poisoning 
in other parts of the country are recorded. In Europe it has long been 
suspected of being poisonous. 
34. Equisetum robustum, A. Br. 
It is common in the state and, like the preceding, is considered poisonous. 
EMBRYOPHYTA SIPHONOGAMA. 
Gymnospermae. 
CONIFERAE. 
Taxaceae. 
35. Taxus canadensis, Willd. American yew. 
Found in northeastern Iowa, especially on calcareous rocks and occasionally 
on sand-stone rock, Linn, Allamakee, and Winneshiek counties. The European 
species has long been regarded as poisonous to stock. Cases of poisoning 
