MR. G. D. HAVILAND: REVISION OF THE NAUCLEES. 13 
lobes are quite distinct and imbricate, and in Mitragyna speciosa 
a single lobe may be many times larger than any of the others, 
simulating the top of the bracteole, but the lobes are never 
filiform or caducous. 
The genus falls naturally into two groups. The one has 
large leaves, corolla-lobes hairy without, anthers not reflexed in 
flower, and short stigma; it consists of two of the three African 
species. The other has smaller leaves, corolla-lobes glabrous 
without, anthers reflexed between the corolla-lobes in flower, 
and stigma longer; it contains the Asian species together with 
M. africana, which is very closely allied to the Asian M. parvi- 
folia. 
The distribution of the genus Mitragyna is singularly different 
from that of Uncaria—it stretches from New Guinea to the 
West Coast of Africa. The most Eastern species is M. speciosa, 
found in Borneo, the Philippines, and New Guinea. M. diversi- 
folia stretches from the Himalayas to the Philippines, Java, and 
the Cocos Islands; M. parvifolia occupies the Indian Peninsula 
and Ceylon, and passes through Burmah to Cochin China. 
M. africana stretches across Africa north of the Equator. 
M. tubulosa, which is a very distinct species, is found in Ceylon 
and in Southern India. The true African species M. macro- 
phylla and M. rubrostipulacea are quite different from the Asian 
species, and must have been separated from them for along time. 
The genera Anthocephalus and Sarcocephalus together form a 
group distinguished at once by the spindle-shaped stigma, and 
by the seeds, though often flattened, not being produced or 
winged. The peduncles are always solitary and terminal, 
except in S. Junghuhnii, in which they may be ternate or some- 
times axillary ; they are jointed below the middle, and the bracts 
are small and functionless. 
In Anthocephalus, though the flowers are crowded, the ovaries 
are not united, or at any rate they are very readily separable ; 
whilst in Sarcocephalus they are so inseparably united as to 
appear to be imbedded in the receptacle. In both species of 
Anthocephalus and in Sarcocephalus esculentus, the African 
species, the placentas are linear and centrally attached as in 
Uncaria; but though in the upper part the ovules imbricate 
upwards, in the lower part the ovules imbricate downwards, and 
the seeds are not flattened or produced. In Anthocephalus 
indicus the upper part of each placenta is bifid, each arm entering 
