CONTRIBUTIONS TO BOTANY. 
127 
— has been denied by Mr. Thwaites, who states that, after ex- 
amining the flowers of Bur sinopet alum in the living state, he is 
convinced that it is valvate. It appears to me, however, that he 
has drawn this conclusion too hastily. I have observed, in the 
flowers of B. arboreum, which are 5-merous, that the margins 
of the petals distinctly overlap each other quincuncially, not to 
any very great extent, it is true, but sufficiently so to render the 
fact incontestable ; besides which, the apices of the petals are at 
the same time deeply inflected (as in Stemonurus) ; but, owing to 
the manner in which these inflected portions are beld together by 
their imbricated plicature, I have found, in attempting to unravel 
the bud, that the petals do not open, because the whole coi’olla 
falls oAF in a cupular form with a slight touch. If the petals in 
this state be spread out radially when held together (as just 
stated) by their apical plicature in the centre, the quincuncial 
character of its aestivation then becomes palpably evident. I have 
seen the flower of Bursinopetalum tetrandrum only in bud, where 
I found the apices of the four petals overlapping each other in 
the apex, the more interior petal being opposite to the more ex- 
terior : this I could not unravel, as the petals adhered together 
so forcibly as to resist the attempt to separate them; but on 
making a cross-section, I observed that, at the junction of the 
petals, the margins were not square and valvate, but were all 
considerably inclined, their chamfered edges overlapping each 
other in a direction corresponding to the indications seen at the 
apex. The extent of this overfolding in the latter species (which 
is the one mentioned by Mr. Thwaitcs) is small, so that under a 
hasty examination it might be mistaken for a valvate junction 
of the margins ; in the former species, the imbricate overlapping 
of the edges is so considerable as to admit of no doubt. 
In the general habit of Bursinopetalum, in the form of its 
simple leaves and simple joints, there is nothing to show any 
approach to the Araliaceae : its inflorescence is always in a tri- 
chotomous panicle, not umbellate as in that family ; the ovary 
is only half inferior, and always unilocular, with a single sus- 
pended ovule : in these respects, as well as in the aestivation of 
the corolla, Bursinopetalum is irreconcilable with Araliacece. On 
the other hand, the form of its calyx, its five petals imbricated 
in aestivation, deeply indexed at the apex, and with an internal 
carinated nervure — its five alternate stamens rising from the 
margin of the ovary, with subulate filaments spreading towards 
the base — a one-celled ovary, with an ovule suspended from a 
longitudinal parietal expansion of the placenta — a simple style 
— a dry 1 -locular drupe, with a coriaceous in dehiscent putamen, 
enclosing a single seed that fills its cavity and is moulded in 
a horse-shoe form round the longitudinal parietal expansion. 
