FLORA OF ADEN. 
153 
the side of the disk (in the Arabian variety). Ovary closely appressed to 
the fleshy disk and half-immersed. 
Flowers : — June (Dr. G. Birdwood in 1867). 
Locality : — Near the tanks (Playfair, G. Birdwood, Collins) ; pro- 
bably not wild in Aden. 
“ Dr. Trimen, F.L.S., exhibited specimens of the Olibanum, or 
Frankincense-tree, Boswellia Carterii, Birdwood, gathered by Mr. James 
Collins at Aden in October 1877.” Proc. Linn. Soc. (Nov. 1877), 
p. XXIV. 
Distribution : — Somaliland, Hadramaut. 
Note : — G. Birdwood’s account of how he came to know and describe 
Boswellia Carterii might, be of interest to Europeans residing at Aden : 
“ When I was placed,” he says, “ in charge of the Agri- Horti- 
cultural Society’s f Old Gardens’ in Bombay, in 1859, I found the tree 
which Carter had brought from Arabia 1 growing there and labelled, 
by Stocks, Boswellia papyri/ era ; and in my catalogue of the Govern- 
ment Central Museum, published in 1862, I adopted Boswellia papyri - 
fera , Bichard, which Royle had called Boswellia floribunda , as the 
source of olibanum; fori had ascertained that Boswellia thurifera , 
Colebrooke, produced none of the olibanum of commerce, but only an oleo- 
resinous exudation. But I had not seen Endlicher’s and Richard’s 
descriptions and figures, nor probably had Stocks ; and I therefore asked 
Colonel (then Captain) Playfair, at Aden, whether he could procure me 
any cutting of the African frankincense-tree. Colonel Playfair sent me 
a large collection of several varieties of dried leaves and of cuttings, 
accurately labelled with their native names, with samples of the kind 
of frankincense which they respectively yielded. At my request he 
subsequently sent duplicates of his dried specimens to Kew. On the 
cuttings which were sent to me striking and leafing, I found that 
I had three kinds : — Yegaar, yielding Luban maitee, an undoubtedly 
new species, and Mohr Add and Mohr Madow, yielding Luban sheheri, 
the bulk of the olibanum exported from the Soumali country. 
Judging by the young leaves solely, I should have been inclined to 
consider Colebrooke’s, Endlicher’s, Richard’s and Carter’s plants, 
and Roxburgh’s Boswellia glabra all only more or less variations of one 
species, and Yegaar the only second species. Indeed, if I followed my 
own erring inclination, I should hold so now. 
1 Cartel found the tree growing in the limestone formation about Merbat and Has 
Fartak. 
