OF ARTS AND SCIENCES. 223 



XIV. 



CONTRIBUTIONS TO AMERICAN BOTANY.* 

 By Asa Gray. 



Presented by Sereno Watson, March 14, 1888. 



Notes upon some Polypctalous Genera and Orders. 



Rutacece. 



Although nature, by supplying various connecting links, mani- 

 festly invites the union of the Simarubacece and Rutacece in one 

 order, yet the exclusion of the former enables the botanist to define 

 the latter order by its pellucid-punctate or otherwise glandular-dotted 

 foliage and the accompanying aromatic or pungent or acrid qualities. 

 But it is difficult to draw the line. 



PHELLODENDRON shows such dots or glauds, few and sparse 

 though they be ; so it should rather be placed with the Xanthoxyla- 

 ceous Rutacece. Otherwise we shall be forced to discard some of the 

 species of the Tobinia section of Xanthoxylum. 



CNEORIDIUM, Hook, f., must more confidently be restored to 

 Rutacece. Hooker, in referring it to Simarubacece, on account of its 

 resemblance to Cneorum, was not aware that this little shrub exhales 

 the odor of Rue, and that the taste is not " acrid," but pungent ; and it 

 is not difficult to see that the leaves, although opaque, have truly and 

 numerously the Rutaceous glands. Occasionally these are manifest in 

 the petals, and they are apparent in the skin of the drupe. Hooker 



* This short paper is a continuation of the one by Dr. Gray in the last 

 volume of the Proceedings, entitled " Revision of some Polypctalous Genera 

 and Orders precursory to the Flora of North America." It contains the notes 

 which he had prepared to present to the Academy upon the Rutacece and Vitacece, 

 the revision of which orders he had taken up immediately after his return from 

 England in October last. He had scarcely commenced his study of the genus 

 Vitis of the latter order when his work upon the Flora of North America 

 ceased. [S. W.] 



