122 Mr. J. Miers on some of the Heliotropieje. 



should be suspended and solitary in their respective cells, with 

 a superior radicle. But it is important to notice that Gaertner 

 distinctly attributes to Beurreria^ 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 

 ovary, with four ovules attached to two bifid opposite parietal 

 placentas — structures only reconcileable with Verbenacece : in- 

 deed De Candolle appeared so far disposed to adopt this view 

 that he suggested the latter genus might be allied to Tectona, 

 Amerinaj however, appears much nearer Githarexylon^ 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 Beurreria 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 Ehretiece and HeliotropiecB : 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 Heliotrojpiece. De Candolle places 

 Tournefortia in Ehretiece ; Fresenius, who has elaborated the 

 Brazilian BorraginecBj ranks that genus in Heliotropiece^ 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 Tiquilia. 

 There remains, therefore, scarcely a tangible uniform character 

 that can mark the limit between Ehretiece and Heliotropiece. 



In regard to Ehretia 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 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 ' Icones,' pis. 1382 & 1383, figures in 

 Ehretia a bifid style upon an ovary which is 1-locular, with 



