27 
THE SO-CALLED AGROPYRON CANINUM (L.) BEAUV. OF 
NORTH AMERICA 
By M. 0. Matte 
CONTENTS Page 
Introduction 27 
Species and varieties in Agropyron 30 
The North American allies of Agropyron caninum (L.) Beauv 34 
Literature cited 48 
Illustrations 
Plate I. Sterile shoots of Agropyron repens (L.) Beauv., and of Agropyron Smithii 
Rydb 49 
II. Sterile shoots of Agropyron dasystachyum (Hook.) Scribn. 1 and of 
Agropyron spicatum (Pursh) Scribn. & Sm 51 
III. Type of Triticum Richardsoni Schrad 53 
IV. Type of Triticum trachycaulum Link 55 
V. Type of Triticum subsecundum Link 57 
INTRODUCTION 
Some years ago, when the writer was in charge of the Division of 
Forage Plants, Central Experimental Farm, Ottawa, particular attention 
was paid to the development of improved strains of hay and pasture plants. 
Among the grasses with which considerable breeding work was undertaken 
was Western Rye grass, commonly known as Agropyron tenerum Vasey, a 
grass comparatively recently introduced into agriculture and now rather 
extensively grown in the Prairie Provinces of western Canada as a hay and 
pasture grass. 
Western Rye grass, a native of North America, occurs in an extremely 
large number of more or less sharply defined forms. While studying this 
polymorphous grass in the field, it was discovered that self-pollination 
apparently takes place regularly. As related elsewhere (ll 2 , pages 
26-27), the discovery was made in 1913 at Edmonton, Alberta, where 
Western Rye grass forms occur in great profusion. The writer, 
when collecting various different forms, observed that the blossom- 
ing presented some features that indicated a mode of pollination different 
from that found in most other grasses. He noticed that during the opening 
process of the flowering glumes, immediately before pollination, the stamens 
did not protrude from between the lemma and the palea, as is normally 
the case in grasses, but remained inside. Examination of the anthers 
further revealed that they were much smaller than in most other species of 
Agropyron . These peculiarities led to a closer investigation of the flowering 
process. In watching the blossoming with the aid of a lens, it was observed 
that when the flowering glumes were in the act of diverging from each 
other, the anthers, while inside the glumes, suddenly exploded, bursting 
open from one end to another, and sprinkling the pollen all over the inside 
of the glumes. At the time of this anther explosion the stigmas were 
'On Plate II this is printed “Vasey”, but should be “Scribn”. 
*The references by numbers are to “Literature Cited," p. 48. 
