CONTRIBUTIONS TO BOTANY. 
191 
a superior radicle. But it is important to notice that Gaertner 
distinctly attributes to Bourreria^ and figures, a 4-carpellary 
fruit, with seeds having an inferior radicle ; and Kunth de- 
scribes his South- American species of Ehretia (formed into 
the genus Amerina by De Candolle) as having a unilocular 
ovaiy, with four ovules attached to two bifid opposite parietal 
placentae — stinctures only reconcileable with Verhenaceoe : in- 
deed De Candolle appeared so far disposed to adopt this view 
that he suggested the latter genus might be allied to Tectona. 
Amerina j however, appears much nearer Gallimrpa^ with 
which it agrees in its tubular persistent calyx, its cylindrical 
5-lobed corolla, with five exserted stamens, the ovary and 
seed being formed as above indicated, having also an arbores- 
cent habit with opposite leaves. The doubts that have been 
throvvTi upon the truth of Kunth’s observations concerning 
Amerina and of Gaertner’s regarding Bourreria are only in- 
ferences founded upon analogy ; but no one has yet shown by 
actual examination that the statements of those botanists are 
contrary to fact. 
It is difficult to draw a line of distinctive characters between 
the Ehretiem and Heliotropiece : some have suggested a sufffu- 
ticose habit in the former, and a subherbaceous one in the 
latter ; but these characters are too variable to be of use : 
others have urged the presence of albumen and a bifid style in 
the former, and the want of albumen with an undivided stigma 
in the latter ; but the former character has been denied to 
Ehretieoe by De Candolle, and I have to show the existence of 
a deeply cleft stigma in Heliotropieee. De Candolle places 
Tournejhrtia 'va. Ehretiem ] Fresenius, who has elaborated the 
Brazilian Borraginem^ ranks that genus in Heliotropiem^ and 
with reason. To the latter tribe has also been assigned the 
distinctive character of a scorpioid spicated inflorescence ; but 
that character is rendered nugatory by the presence of solitary" 
axillary flowers in Goldenia and in many species of Schleidenia^ 
and of several congested single axillary flowers in Tiquilia. 
There remains, therefore, scarcely a tangible uniform character 
that can mark the limit between Ehretiem and Heliotropiem. 
In regard to Ehretia I will not venture to offer any decided 
opinion, because I have had no oppoi'flz.iity of examining its 
species ; but we are evidently much in the dark concerning 
its real structure. All authors agree in attributing to Ehretia 
a 4-locular ovary with a slender simply 2-fid style, a single 
ovule suspended from the summit of each cell, and a baccate 
fruit enclosing a 4-celled nut, or two nucules, each 2-celled. 
But Dr. Wight, in his ‘ leones,’ in pi. 1383 obscurely, and in 
pi. 1382 distinctly figures in Ehretia a bifid style upon an ovavy 
VOL. II. 2 C * 
