98 Rhodora [Max 
ELYMUS ARENARIUS AND ITS AMERICAN 
REPRESENTATIVES. 
Hanorp ST. JOHN. 
Elymus arenarius L. of the sea beaches and sand dunes of the 
European coasts was known to the early botanists and was treated 
by Linnaeus in his Species Plantarum.! As this species is well marked 
among its European relatives it has had a simple and uneventful 
history in botanical literature of the old world. The only question 
causing any serious difference of opinion is whether Elymus sabulosus 
Bieb. should be treated as a variety of E. arenarius or as a distinct 
species. Differing from the latter by its more vigorous growth, by 
its larger number of spikelets at a node, by its stiff awl-shaped gla- 
brous glumes, by its lemmas glabrous from the middle to the tip, by 
its shorter anthers (4.5-5 mm. long), and by its smaller grain (6 mm. 
long, 1.5 mm. broad), this plant of southern Russia and Siberia with 
a range scarcely touching that of E. arenarius, seems to the writer 
to be specifically distinct. An earlier name, however, must displace 
E. sabulosus Bieb. Without a known locality, but fourteen years 
earlier, Elymus giganteus Vahl.? was described in terms quite appli- 
cable to the plant which has so long passed as E. sabulosus. In some 
of the larger herbaria are specimens of a plant grown in cultivation 
under the name Elymus mexicanus Cav? which is indistinguishable 
from E. giganteus Vahl. The great amount of botanical collecting 
done in Mexico since Cavanilles described his E. mexicanus has not 
established this as one of the native species and its perfect agreement 
with E. giganteus of southern Europe and Asia indicates that Roemer 
and Schultes were correct in reducing E. mexicanus to a synonym 
of E. giganteus Vahl. 
In North America the group of coastal species with awnless broad 
glumes and awnless lemmas, in which E. arenarius is included, has had 
a much more eventful bibliographical history. Kalm detected the 
1 L. Sp. Pl. i. 83 (1753). 
! Vahl, Sym. Bot. iii. 10 (1794). 
3 Cav. Descr. Pl. 314 (1802). 
! Roem. & Schult. Syst. Veg. ii. 774 (1817). 
