- 
eae BOTANICAL GAZETTE [ APRIL 
Whatever the cause, a slowly advancing lee slope is soon cap- 
tured by vegetation. The process begins just as described above. 
Vegetation gets a foothold at the base and creeps up the slope. 
Antecedent plants, like dogwoods and willows, increase their 
area by vegetative propagation. Annuals, biennials, and even 
the hardier perennials germinate and successfully develop at all 
points. There are many plant species whose power of vertical 
growth is greater than the vertical component of a slow dune's 
advance. This latter condition is always the chief test which 
determines the vegetation of a lee slope. As the advance 
becomes slower, more and more plant species are able to get and 
retain a foothold on the dune. 
The capture of lee slopes by vegetation was well seen in all 
its stages at Glen Haven and Grand Haven. At first the vege- 
tation may be dominantly antecedent, as in the case at Dune 
Park. More commonly, however, the vegetation is chiefly sub- 
sequent from the start, chiefly because the area that is encroached 
upon contains no plants that are fitted for a dune life. Where 
there is no antecedent vegetation, the first plant to get a foot: 
hold is commonly Ammophila arundinacea. Plants that follow in 
quick succession are Asclepias Cornutt, Equisetum hyemale, ala- 
magrostis longifolia. Some dunes are almost completely covered 
with a dense growth of Ammophila. All of these plants are per 
ennial herbs and all but Calamagrostis have very extensive vege 
tative propagation, so that the capture of a slowly moving — 
isa relatively quick process. With these plants there wee Has 
annuals and biennials, but they are of little or no value a y 
capture. The commonest of these is Corispermum aesene” 
Before many years have passed shrubs and small ghia 
an entrance and gradually drive out the herbaceous ine 
described in the preceding paragraph. These herbs a a ey 
to grow in the most exposed situations, but are not @ gh be 
shade. The shrub vegetation of arrested lee slopes n spe 
partly antecedent, but not largely so. The most comme “4 
cies of shrubs on recently captured slopes are Corme cordifolia 
(or C. Baileyi), Salix adenophylla and glaucophylla, i 
