130 Mr. J. Miers on the Affinities of the Olacaceae. 



(Linn. Trans, xviii. p. 682) considered "that among dichlamy- 

 deous plants, they come nearest to the Olacinece ', " but in this 

 conclusion, as I stated before, he had probably in view his tribe 

 Icacinece, where in Pogopetalum there is sometimes a similar large 

 fleshy connective, forming a conspicuous appendage much exceed- 

 ing the length of the anthers, and it has also an ovarium of 

 several cells with two ovules suspended from near the summit. 

 In Stemonurus we find similar glandular cilia upon the filaments. 

 In Ptychopetalum we have double the ordinary number of sta- 

 mens, and in several genera of the same tribe, we perceive a 

 hypogynous cup, with ten free lobes, investing the base of the 

 ovarium. They resemble the Icacinaceee also much in habit, 

 having similar coriaceous exstipulate leaves, and terminal or axile 

 inflorescence of small crowded flowers, each flower being sup- 

 ported on an articulated pedicel. Notwithstanding these distant 

 indications, the real affinity of the Humiriacece appears to me to 

 be nearest the Styraceee. 



While speaking of the latter family, I will offer a passing ob- 

 servation upon the anomalous genus Diclidanthera, placed doubt- 

 fully by Von Martius in Ebenacece or Styraceee, by Lindley in 

 Styracea, by Don in Ebenacea, and by Endlicher in Styraceee. 

 Prof. A. DeCandolle in his ' Prodromus * (vol. viii. p. 245) has 

 given several reasons why it should be excluded from the last- 

 mentioned order, but has not assigned to it any other position, 

 and since then no other botanist has ventured to indictae its true 

 locality in the system. I shall be able to demonstrate that its 

 corolla is not gamopetalous, as generally stated; or at least 

 that its petals are easily separable from each other, being only 

 slightly agglutinated together by the feeble adhesion of the fila- 

 ments to them. In its habit, its stipular alternate leaves, the 

 linear form of its petals, their mode of aestivation, the stamens 

 always double the number of the petals, the valvular and hinge- 

 like dehiscence of its anthers, the suspension of a single ovule 

 from the summit of each cell of its ovarium, the form and direc- 

 tion of the embryo with large foliaceous cotyledons in fleshy al- 

 bumen, Diclidanthera will be seen to approximate closely to the 

 Hamamelidacea, from which family it differs only in some slight 

 characters, principally in the absence of the fleshy hypogynous 

 disk that in Hamamelis and its congeners serves to agglutinate 

 the base of the ovarium with the lower portion of the tube of the 

 calyx, and which thus renders it semi-inferior. 



Whether for this reason, it will form the type of a distinct 

 Order, is a point to be determined when the family of the Ha- 

 mamelidacea has been better investigated ; but its proximity is 

 certainly here, and in the meanwhile it may be desirable to 

 place it in a separate tribe of that order. 



