The Geographical Distribution of the Frankeniaceae ete. 401 
for it produces great abundance of seeds, which find ready escape from the 
capsule, and being very tiny grains, !/; mm in the longer diameter, are 
easily carried by the wind like light grains of sand, or by coast birds, and 
so have comparatively free interchange between regions united by coast or 
sand steppes. As to the relation of F. pulverulenta to the Australian and 
the Chili-Californian regions, a more difficult question of distribution is 
involved which will be discussed with the corresponding species of those 
regions. 
Concerning the distribution of the polymorphous, shrubby forms of 
Eufrankenia it may be said that two, F. laevis and F. hispida incl. var. 
erecta, producing many tiny seeds like F. pulverulenta, enjoy also a com- 
paratively wide distribution ; but they do not possess the capacity for dis- 
tribution, if one may so express it, of F. pulverulenta, which illustrates that 
other important factors independent of seed production and seed distribu- 
tion influence the distribution of nearly related species. The other shrubby 
forms produce for the most part fewer seeds and are restricted to a very 
local distribution. This difference in distribution capacity between the an- 
nual F. pulverulenta and the perennial shrubby species lies probably in 
this very fact of the life period of the individual, wherein is also to be 
sought the constancy of the one species and the many variations of the 
other. F. pulverulenta is not necessarily associated long with the conditions 
of any one spot, but springs up, bears its seed quickly and so repeats itself 
constantly under conditions which are in a sense of its own choosing. The 
shrubby perennials are, however, not so independent of environment. 
Slower to find a foot hold they are bound to it permanently and receive in 
the course of time the effects of imposed conditions. The perennial type 
has come, ultimately, to a distribution approximately as wide as F. pulveru- 
lenta, but it has not been able to do so without passing into manifold va- 
riations. 
In connection with the Frankeniaceae of the Mediterranean region two 
facts deserve here preliminary mention: 4. That throughout this very broad 
region the species are so nearly related as to fall in the one section Eufran- 
kenia (the genus Hypericopsis is the one interesting exception). 2. That 
the species of this region stand in a very intimate relation to a similar de- 
velopement in Australia and the Western Hemisphere. 
Hypericopsis. 
Hypericopsis persica (Jaub. et Spach.) Boiss. is the one instanee among 
Frankeniaceae where the chief distinguishing character is based upon a de- 
parture from the type in floral structure unaccompanied by corresponding 
changes in plant habit. This plant corresponds in vegetative structure to 
the F. hispida var. erecta which is also found in south-eastern Persia where 
H. persica is endemic. The constant occurrence of many stamens, 20—24, 
Bctanische Jahrbücher. XXIV. Bd. 26 
