1907] BRIEFER ARTICLES 213 
A. arcuata graminijolia Casp. Schrift. Phys. Okon. Gesellsch. Kénigs- 
berg 25:ii. 1884. A. arcuata aquatica Celak. 1. c. 417.—Totally or partly 
submersed. All or most of the leaves swimming, linear, from a few to 
too®™ long, without blades (or one, or a few of the leaves with a linear- 
lanceolate blade, either swimming, or on a stiff petiole reaching above the 
surface of the water). Inflorescence more or less emersed or even sub- 
mersed. Where the water is getting lower, it passes into var. lanceolatum, 
and plants with linear leaves without blades (phyllodes), within three or 
four weeks, with the gradual lowering of the water-level or disappearance 
of the water, have been transformed into typical specimens of var. lanceo- 
latum, according to repeated observations by myself and others. 
According to BUCHENAU, A. arcuatum is distributed only over central 
Europe, northern Africa, and western Asia (to Persia and western Siberia). 
To this belt of territory can now be added North Dakota, where I have 
found var. pumilum along Oak Creek, near Bottineau, and the other two 
varieties at Leeds and York. They have been collected during the 
months of July and August. 
In the above presentation some additions of characters have been made 
to the original descriptions, and also some modifications thereof, to con- 
form with conditions existing in North Dakota; but none of them has 
changed the essential features of the species. J. Lunett, Leeds, North 
akota. 
