70. Rhodora [APRIL 
with 3 florets, 7 with 4 florets, 25 with 5 florets, 24 with 6 florets, and 
2 with 7 florets. The variation in number of leaves in a whorl was: 
2 with 2 leaves (poor specimens), 20 with 3 leaves, 36 with 4 leaves, 
and 2 with 5 leaves. 
ConRNELL University, Ithaca, New York. 
THE AMERICAN AMMOPHILA. 
M. L. FERNALD. 
THE common Sand Reed, Psamma, Marram or Beach Grass, which 
covers the coastal sand dunes from the Straits of Belle Isle to North 
Carolina and occurs on sandy shores of the St. Lawrence system 
inland quite to Lake Superior, has been universally identified with 
Ammophila arenaria (L.) Link, the species occurring on the western 
and southern coasts of Europe. Superficially the two are very 
similar, although it needs only a glance at good material of typical 
A. arenaria, which occurs from southern Scandinavia to Portugal 
and Morocco, to see that the spike-like panicle is much shorter than 
in most of the American plant, A. arenaria having panicles only 0.5-2 
dm. long, the panicles of the Atlantic American plant ranging from 
1.5-4 dm. in length. In its long panicle the American plant is more 
nearly approached by the Mediterranean A. arenaria, var. arundinacea 
(Host) Husnot, in which the panicles may be 3 dm. long. 
In all its technical characters, however, the long-panicled Mediter- 
ranean Ammophila arenaria, var. arundinacea agrees with the more 
northwestern typical European A. arenaria; but in these characters 
the European and Atlantic American plants are quite distinct, the 
Old World species being known in America only on the Pacific coast, 
where it has very recently been introduced as a sand binder. Briefly 
stated, the two species differ as follows: In A. arenaria the upper 
surface of the leaf-blade is copiously puberulent along the cartilaginous 
nerves, in the American merely serrulate-scabrous; in A. arenaria 
the ligule is scarious, lance-attenuate and very prolonged, commonly 
1.5-3 em. long, and lacerate at tip; in the Atlantic American plant, 
on the other hand, the ligule is chartaceous or coriaceous, rounded 
and very short, ranging from 1-3 mm. in length. In A. arenaria, 
