FRANKINCENSE. 279 
viz., the B. Frereana, Birdwood. Kempthorne thus describes 
it * :—“ The tree is one of the most extraordinary plants I ever saw, 
quite a dusus nature of the vegetable world, for the trees actually 
grow out of the sides of the almost polished rocks. ... The trees 
were about 40 feet high, the stem was about 2 feet in circumfer- 
ence, rising straight up, with a bend outwards of 6 or 7 inches. 
They are attached most firmly to the rocks by a thick oval mass of 
substance, about a foot or so in diameter, something resembling a 
mixture of lime and mortar. Branches spring out rather scantily 
at the top and extend a few feet down the stem; the leaves are 5 
inches or so long and 14 broad, narrowing and rounding towards 
the point, but not serrated at the edges; the upper surface is of a 
rich dark shining green, while the lower is of a lighter hue; they 
are thin and smooth, and crimped like that beautiful species of 
seaweed so often found on the coast of England. The tree has 
four layers of bark, the outer being coarse and loose, like that of 
the beech, while the next two are as it were glued to the trunk 
and delicately fine, resembling ,oiled paper or gold-beaters’ skin, 
and of a bright amber colour; this bark is perfectly transparent, 
and can be stripped off easily in large sheets; the natives use it 
for writing on. The inner bark of all is an mch or so in thick- 
ness, adhering closely to the stem; it is tough, not unlike leather, 
striped red and white, and yields a strong aromatic perfume. 
The timber is white, soft, porous, and of little use except as fire- 
wood. A deep incision into the bark causes the odoriferous resin 
to exude in large quantities, which is of a milky white and of the 
consistency of honey; but it soon hardens by exposure to the 
atmosphere. It isa remarkable fact that not a single frankin- 
cense-tree did I perceive growing upon any other rocks than those 
of almost pure limestone.” 
Dr. Birdwood concludes his description of this tree as follows 7 : 
“ As I saw this plant in Playfair’s garden at Aden in September 
last, m young leaf and covered with bloom, I was much struck 
by its elegant singularity. The long racemes of green star-like 
flowers, tipped with the red anthers of the stamens (like aigrettes 
of little stars of emerald set with minute rubies), droop gracefully 
over the clusters of glossy glaucous leaves ; and every part of the 
* Trans. Bombay Geo. Society, xiii. 1857. 
t Trans. Linn. Soc. xxvii. p. 148. 
