
          -17-

there is a precipitation gradiant [gradient] of decrease from West to East,
so that the longitudinally aligned Zagros range exerts a screening
effect in the same way that the Sierra Nevada range does in
California.

The seeding season of this area follows that of the desert
lowlands rather closely and occurs generally between June 1 and
August 1.  Perennial grasses and legumes, however, are much better
developed in species and palatability.  Among the prominent forage
genera are Bromus, Stipa, Oryzopsis, Hordeum, and Onobrychis with
obvious xerophytic and survival characters of value.  Browse is also 
afforded by a wide range of spiny or shrubby or low perennial species
in such families as Compositeae, Polygonaceae, and Leguminoceae.
Palatable legume perennials are very scarce, being limited generally
to scattered individuals protected or hidden by impalatable bushes
or to such dodgers as spiny Astragalus, Lycium, and Mimosaceae.  Due
to rapid drying of soil in the late spring months, seed suddenly
matures in a short seeding period at any given locality;  perhaps of as
little duration as two weeks.  The bromes appeared to go to seed especially
fast.  I was told by the Iranians that spring rains had generally
been very light and this seasonal condition doubtless accentuated 
the rapid maturation of seed with the short growing season.  I
found seeding most abundant generally through latter June and early
July.  Additional general descriptive notes of the vegetation types
and the seed collections are given in the above enclosed field account
of May 20.
        