S66 Dr. Walker-Arnott on Samara Iseta, Linn. 



Linnean sterile one. In the Banksian plants the petals are of a thicker texture 

 than in either of the others, particularly their lower half towards the margins, 

 as if the margin had been inflexed and become adnate to the inner surface 

 of the petal : there is also a conspicuous canal behind the filament, and to 

 which the latter is applied : the petals are of a much darker colour than in the 

 Linnean sterile one, and agree better in that respect with the Linnean fertile 

 ones. The dots or glands on the petals are oblong and very obscure ; in all 

 the three Linnean specimens these are round, and in the sterile plant are very 

 conspicuous. In the Linnean fertile plant the petals exhibit a small lobe at 

 the base folded up against the face of the petal, and more or less agglutinated 

 with it, although occasionally I find it free : the space between these lobes 

 forms the " fossula" of Linnaeus. In the sterile specimen there was a similar 

 structure. 



A question now arises whether there be one, two, or even three distinct spe- 

 cies. They all agree, as I have said, in several particulars ; on the other hand, 

 the bark of the fertile specimen exhibits numerous small, prominent, but con- 

 spicuous tubercles or lenticellae, which are either wanting or much less con- 

 spicuous on the Linnean sterile one : I am inclined however to consider this 

 difference as connected with the portions of the shrub from which the specimens 

 have been taken, as I find similar differences on specimens of what I consider 

 to be Choripetalum aurantiacum, Alph. DeCandoUe. The principal distinc- 

 tions lie between the sterile plants, those in the Banksian herbarium having 

 short but perfect stamens, while in the Linnean one the stamens are elongated ; 

 and as the three in the Banksian collection agree with each other, although 

 collected by different individuals and at different times, I can scarcely attri- 

 bute the shortness of the filaments to the flowers not being sufficiently deve- 

 loped, although I consider that is the reason for only one flower on the Linnean 

 specimen having long stamens. As to there being three species confused, I 

 see no reason for such an hypothesis, the differences between the Banksian 

 specimens and the Linnean fertile ones being scarcely greater than might be 

 expected in flowers of different sexes. The principal difficulty lies in the Lin- 

 nean sterile specimen ; but, on the other hand, it agrees better, in the petals 

 having their inflected portion confined to the base, with the fertile plants, than 

 with the Banksian specimens. 



