Mr. J. Miters on the EHretiacese. 107 



merated by DeCandolle enter into the genera Bourreria and 

 Crematomia : these are distinguishable at a glance from Ehretia 

 by their much larger, tubular, fleshy calyx, terminated by five 

 teeth with thick tomentous margins, which are valvately closed 

 in gestivation, and afterwards sometimes adhere so strongly 

 together as to be separable with difficulty. 



The Ehretia spinosa of Jacquin, judging from the characters 

 he assigned to it, appears to differ in no way from Bhabdia, 

 except in the pointed extremities of its deeply bipartite style : 

 this plant constituted the second species of Don's unrecognized 

 and incongruous genus Lutrosti/lis, the type of which, the 

 Ehretia fasciculata of Kunth, is of very different structure, 

 and will presently be noticed ; his third species was the Ehretia 

 montevidensis of Sprengel, which, from Sellow's original spe- 

 cimen in the Berlin Herbarium, has proved to be the Citha- 

 rexylon barbinerve of Chamisso. 



It has already been mentioned that there exists in the or- 

 ganization of the ovary and fruit of the Ehretiacece a point 

 of structure which has escaped general observation : this 

 is, the placentation of the ovary, and the existence of a 

 gynobasic or central column which furnishes the nutrient ves- 

 sels for the growth of the ovules ; the course of these vessels 

 may always be traced through apertures existing in the nu- 

 cules where they terminate in the funicular points of suspen- 

 sion of the seeds. Hence the frequent geminate connexion of 

 the distinct nucules in pairs in this family, a connexion effected 

 either through a chink on one side only of each cell, some- 

 times near the summit (as I have already shown in Bhabdia, 

 ante, vol. ii. p. 432), or sometimes, through the intermedium of 

 a pseudo-cell, from a large opening above the base, as is seen 

 in Bourreria : these modifications furnish good characters, 

 which mark the different genera of the Ehretiacece, and which 

 serve at once to distinguish this family from the Cordiacece, 

 Heliotrojjiacea'j and Borraginaccce. 



The folloAving is a reformed diagnosis of the genus under 

 consideration : — 



Eheetia, Linn. — Calyx parvus, persistens, subcampanulatus, 

 imo crassiusculus, fere ad basin 5-partitus, laciniis subovatis 

 aut subulatis, margine membranaceis et ciliatis, asstivatione 

 imbricatis. Corolla gamopetala, hypogyna, membranacea, 

 tubo srepius calycis longitudine aut paulo longiore, limbi 

 lobis 5, oblongis, tubo paulo longioribus, revolutim expansis, 

 aastivatione valde imbricatis. Stamina 5, alterna ; jilamenta 

 compressa, subulato-filiformia, tubo affixa, exserta ; aniherce, 

 ovatas, 2-loba3, imo ad medium divaricata 3 , locellis sine con- 



