list of figures - Terry Sunderland

CHAPTER ONE
MORPHOLOGY AND BIOGEOGRAPHY OF AFRICAN RATTANS
1.1 INTRODUCTION
The rattans of Africa are represented by the endemic genera Laccosperma,
Eremospatha and Oncocalamus, as well as by a single representative of the Asian
genus Calamus. These climbing palms occur in a wide range ecological conditions
within the lowland tropical forests of the continent and, throughout their range, play a
significant role in the forest economy of the region through the utilisation of the inner
stems, or cane. Despite this economic importance there has persisted considerable
uncertainty with regard to the natural history of these species. This Chapter discusses
the morphology and wider natural history of these species and provides the basis of
the taxonomic revision presented in Chapter 2.
1.2 MORPHOLOGY
1.2.1 Growth form
All the rattan species of Africa are clustering i.e. they produce numerous stems from
one individual. The suckers that develop to form a cluster are produced from the
lowermost nodes of the original stem. They, in turn, produce further suckers and a
large clump then develops (Dransfield, 1992a). Within the taxa of African rattans, the
suckers are produced in the axils of the basal-most leaves and this is commonly the
case with most clustering species of rattan. However, in a few instances (e.g. some
species of the Asian genus Daemonorops), the sucker shoots are produced opposite to
the leaf, whilst the vegetative buds of Korthalsia, another Asian genus, appear to be
intermediate between axillary and leaf-opposed (Fisher and Dransfield, 1979).
Although in general, rattan species are consistently single-stemmed or clustered it is
possible to encounter individuals of predominantly clustering species with only a
single stem e.g. the Asian species, Calamus subinermis H. Wendl ex Becc. This is
sometimes the case with some normally clustering Eremospatha species in Africa,
particularly in closed-canopy forest where the lack of light penetration could possibly
be a limiting factor to the development of the cluster.
21