10 MR. G. D. HAVILAND: REVISION OF THE NAUCLEE. 
peduncles are found on the same plant; and in Adina there is 
one species which has simple terminal peduncles, and other 
species which have simple lateral peduncles. In the great 
majority of species the peduncles are simple, though in several 
species they are compound. It often happens when a simple 
peduncle is terminal that two others arise at its base in the axils 
of the leaves on either side, the peduncles then being simple 
and ternate; this condition is common in Uncaria and Nauclea. 
In a single species (Adina cordifolia) the peduncles though 
axillary are simple and ternate, standing three together in a 
vertical plane. The peduncles may become compound by 
branching in the axils of the bracts, a secondary peduncle being 
given off in the axil of each foliaceous bract; the secondary 
peduncles are then themselves provided with bracts, though the 
original peduncle has no additional pair, so that the centre 
flower-head appears to be on a much shorter peduncle than the 
lateral ones. This branching of the peduncle occurs abnormaliy 
in Nauclea, but normally in Mitragyna, in which genus the 
secondary peduncles may themselves give off lateral peduncles 
from the axils of their foliaceous bracts. In some species of 
Uncaria the lateral peduncles may give off branches; but they 
then present two or three superposed sets of joints and bracts, 
more than one of which may give off branches. It may also 
happen in Unearia that the leaves at the bases of the lateral 
peduncles are imperfectly developed, and the inflorescence then 
has the appearance of a racemoid cyme. In the African species 
all the lateral peduncles frequently remain sterile, the central 
terminal peduncle alone bearing flowers. In Mitragyna macro- 
phylla it is not uncommon for the peduncle at the joint to split 
up into a large number of secondary peduncles of nearly equal 
size and length, so that the flower-heads are umbellate. 
The stipules are generally interpetiolar and deciduous, but in 
three species of Sarcocephalus they are intrapetiolar, amplexicaul, 
and subpersistent. In Mitragyna and Anthocephalus they are 
very large, in the former genus broad and flat, but in tbe latter 
they enfold the bud. In the genera Adina, Cephalanthus, and 
Uncaria the stipules are smaller and frequently bifid. 
All the species of Uncaria are climbing shrubs: those 
of other genera are erect, either trees or shrubs, although 
Sarcocephalus esculentus is said sometimes to climb. Sometimes 
the trees are of large enough size to provide timber, more often 
