[Vol. 8 
114 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
been confirmed by a comparative survey of the ovule number in 
the species concerned. 
The Seeds.—In this genus the seeds offer little of diagnostic 
value. Four species have definitely winged or margined seeds. 
These species are the same that have been previously mentioned 
as having auriculate stem-leaves and they belong to the three 
sections. They have already been designated as possessing 
more primitive characters than any other four species, and con- 
sequently this seed character is probably to be considered most 
primitive also. Throughout the genus the relative position of 
the cotyledons and the radical is nearly constant and is described 
by the adjective ‘‘accumbent.”’ In this case the radical is ap- 
plied to the edge rather than to the back of the cotyledons and 
in cross-section may be diagrammatically represented thus: 
o=. In perhaps six species the radical is not centrally placed 
but twisted slightly to one side and the cotyledon on that side 
is slightly shorter than on the other. This condition is considered 
derived, since it occurs in widely diverse and evidently terminal 
species. 
The Trichomes.—In the past, attention enough has been paid 
to the character of the trichomes in cruciferous plants to make 
it imperative that they be considered critically in any study in 
any group of species of this family. Many taxonomists have 
segregated genera largely on the character of the trichomes and 
some have gone so far as to distinguish tribes by the simple or 
branched hairs. In Lesquerella the species are more or less 
densely clothed with variously branching hairs which in many 
cases give them a silvery gray color. Simple trichomes occur 
regularly in but three species, and in these they are not numer- 
ous nor conspicuous and must be searched for with the lens; in 
a fourth they may be found occasionally. These four species 
are the same as have been mentioned several times as most 
primitive and are further characterized by auriculate stem- 
leaves, winged seeds, and filaments with dilated bases. In these 
species the branched hairs are frequently not truly stellate by 
reason of the central ascending axis with branches produced at 
several heights. Even in the truly stellate hairs the branches 
are few and always distinct. In the variation of the trichomes 
in any of the three first-mentioned species, L. Lescurit, L. lasio- 
