360 Mr. CoLEBROOKE on Boswellia 



but most entire. For instance, Amyris jmnctaia, A. sumatrana, 

 and A. heptaphylla of Roxburgh. (This hist is not to be con- 

 founded with Aublet's Idea lieptaphylla, which is the Amyria 

 amhrosiaca of Willdenow.) In all three the nectary is a large 

 fleshy receptacle, separated from the receptacle of stamina and 

 petals by a strangulation or contraction, which leaves an upper 

 protuberance to uphold the germ, and a lower to receive the 

 filaments and petals. The mature fructification of two of these 

 plants has been observed and described. The seeds have no 

 osseous covering, but a single tender integument. Their coty- 

 ledons are simple ; Hat on the contiguous sides, and convex, 

 conform to the seed, on the outer surface. 



Perhaps another division might be proposed for such plants 

 as have a nectary distinctly glandular. For example. Commi- 

 phora Madagascariensis of Jacquin, the same with Roxburgh's 

 Amyris Agolloc/ui. Its nectary consists of as many glands as 

 there are stamina, situated at the insertion of these. I3ut the 

 fruit of this species has not been yet inspected, nor even the 

 hermaphrodite tlower. Roxburgh, as well as Jacquin, was 

 unable to find any besides male tlowers. 



It does not, however, appear in other instances, where the 

 complete fructification has been examined, that those differences 

 in the nectary precisely correspond with primary ditl'erences 

 observable in the mature fructification, on which, as I appre- 

 hend, reliance is to be ultimately placed for a main ground of 

 generic distinction. Yet it is material to attend to the nectarial 

 character in this group of plants. If the staminiferous disk be 

 connected, as in my view it is, with tlie germ rather than with 

 the calyx, it determines the hypogynous insertion of the sta- 

 mina ; and consequently shows the necessity of disjoining these 

 plants from the perigynous order of Terebinthacece, with which 

 they have been associated. In this remark I rely on the maxim, 



that 



