122 Mr. J. Miers un some of the Heliotropiee. 
should be suspended and solitary in their respective cells, with 
a superior radicle. But it is important to notice that Gaertner 
distinctly attributes to Beurrerta, and figures, a 4-carpellary 
fruit, with seeds having an inferior radicle; and Kunth de- 
scribes his South-American species of Hhretia (formed into 
the genus Amerina by De Candolle) as having a unilocular 
ovary, with four ovules attached to two bifid opposite parietal 
placentee—structures only reconcileable with Verbenacew : in- 
deed De Candolle appeared so far disposed to adopt this view 
that he suggested the latter genus might be allied to Tectona. 
Amerina, however, appears much nearer Citharexylon, 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 
thrown upon the truth of Kunth’s observations concerning 
Amerina and of Gaertner’s regarding Beurrerta 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 difticult to draw a line of distinctive characters between 
the Hhretie and Heliotropiew: some have suggested a suffru- 
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 
Ehretiece by De Candolle, and I have to show the existence of 
a deeply cleft stigma in Heliotropiew. De Candolle places 
Tournefortia in Ehretiee ; Fresenius, who has elaborated the 
Brazilian Borraginee, ranks that genus in Heliotropiew, and 
with reason. ‘To the latter tribe, again, has been assigned the 
distinctive character of a scorpioid spicated inflorescence ; but 
that character is rendered nugatory by the presence of solitary 
axillary flowers in Coldenia and in many species of Schleidenia, 
and of several congested single axillary flowers in 7%quilia. 
There remains, therefore, scarcely a tangtble uniform character 
that can mark the limit between Hhretiew and Heliotropiee. 
In regard to Hhretia I will not venture to offer any decided 
opinion, because I have had no opportunity of examining its 
species; but we are evidently much in the dark concerning 
its real structure. All authors agree in attributing to Hhretia 
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 ‘ Icones,’ pls. 1882 & 1383, figures in 
Ehretia a bifid style upon an ovary which is 1-locular, with 
