60 MR. G. BENTHAM ON AUSTRALIAN PROTEACEAX. 
As a good example of the style of the regular straight flower 
we may take that of Petrophila longifolia (Plate I. fig. 1), the upper 
portion of which is usually described as a biarticulate stigma. But, 
in the first place, there is no articulation ; the upper portion, which 
may here well be called the brush, does not separate from the lower, 
and neither portion is stigmatic on the surface. The brush, a 
dense mass of short papillose hairs, corresponds exactly in length 
with the anthers, and collects their pollen ; at the end and shut out 
from all contact with the pollen by the closed ends of the anthers, 
is the small stigmatic surface, which, besides its immaturity, is 
further protected by being closely applied to the inflected tips of 
the perianth-segments. The part played by the so-called lower 
article, the expanded turbinate end of the smooth part of the 
style, is not very clear; it probably acts as an impediment to the 
premature escape of the pollen through the perianth-tube, or 
possibly by its expansion assists in the forcing open of the 
segments. This distinction of the brush and turbinate base, how- 
ever, is not so marked in all Petrophile; the brush is some- 
times very thin and slightly papillose, tapering at the base into 
the slender style, the papillose portion extending always only 
to the base of the anthers. 
In the very natural genus Persoonia there are three sections, 
showing two very different stigmatic arrangements. In <Acran- 
thera and Amblyanthera (Plate I. fig. 2) the style is straight 
and, as in Petrophila, has a papillose, furrowed, or viscid portion 
enclosed within the anthers, whilst the stigma protrudes beyond 
them, the more or less disk-shaped summit being alone stigmatic. 
In Pycnostyles (Plate I. fig. 3) the style is short and very 
thick, just reaching to the base of the anthers ; but, in order to 
escape all chance of contamination from them, it curves round, 
turns its back upon them, and buries its small stigma in safety in 
a protuberance or pouch prepared for it near the base of the 
perianth-tube, from which it is only released by the fall of the 
segments with their then empty anthers. As a further security 
in some species the anther immediately over the pouch in which 
the stigma is buried is almost, or quite, without pollen. 
In Banksia (Plate I. fig. 4) and several other genera the 
style, as in Persoonia (Pycnostyles), reaches only to the level of 
the anthers, but without any safeguard, as far as I can detect, 
against contamination by the pollen, except the immaturity of the 
stigma. In most of these flowers the perianth is much curved 
