466 M.E. Boissier on new Facts in Botanical Geography. 
Adesmia, a shrub belonging to the family Leguminose. M. 
Guillemin found that it formed a new genus, which he de- 
scribed under the name of Pilostyles. It has no root, stem, or 
leaves, and consists only of a campanulate flower of 2 lines in 
length, sessile upon the bark of the Adesmia, the epidermis of 
which it tears during its development. It is dicecious; and 
hitherto only the male plant is known. The flower is surrounded 
at the base by a few bracts, and consists of a calyx of four 
oblong and imbricated parts, of a corolla with four spathulate 
petals, also imbricated, and exceeding the calyx a little, and, 
lastly, of a thick, short, obtuse central column, which is attenu- 
ated in its lower half and surrounded about the middle by a 
ring formed of three rows of unilocular anthers, above which 
there is another, narrower one, composed of closely approximated 
papilla. This column is solid, and formed of cellular tissue ; 
but a transverse section, when magnified, shows the orifices of a 
very few isolated trachez. The flowering over, the flower falls, 
leaving a concave depression upon the bark of the Adesmia. 
This curious production of flowers with no stalks gave rise at 
first to the strange notion that the Pilostyles is only a mon- 
strosity of the normal flower of the shrub on which it grows; 
but this opinion could not maintain its ground for a moment in 
the presence of the details of structure and the non-axillary 
insertion of this singular plant, which may be arranged very 
naturally in the family Rhizanthee, as a miniature of those 
gigantic Rafflesie which, in the Sunda islands, are parasitic upon 
the roots of other shrubs. 
The naturalist Pohl also brought from Brazil a second species 
of the same genus, growing upon the branches of a Bauhinia; 
but for many years no new fact has been added to the history of 
Pilostyles wntil this winter, when, in examining a collection of 
dried plants collected in the alpine region of the mountains of the 
east of Asia Minor by M. Haussknecht, I found the branches of 
a spiny Astragalus covered at the base and round the points of 
insertion of the leaves with small reddish globular bodies which 
immediately reminded me of the Chilian plant. It was, in facet, 
a Pilostyles, resembling P. Berterii in all its principal characters, 
but differing specifically in the absence of bracts, the shorter 
flower, and having the pieces of the calyx and corolla to the 
number of five or six instead of four. My friend Dr. J. Miller 
has been kind enough to make a very particular microscopic 
analysis of this curious production, and has found other differ- 
ences. Thus, in the oriental plant, the ring of unilocular anthers 
round the central column is formed of two instead of three rows 
of anthers; the column itself is shorter, and is not narrowed in 
its inferior portion. It is a very singular fact, that whilst the 
