3. INTRODUCTION
Members of the family have leaves opposite each other with
stipules or in whorls, unbroken leaf margins, and leaf like
appendages at the base of the leafstalks. The leaves usually are
large and evergreen in tropical species, deciduous in temperate
species, and needlelike or scale like in desert species. The plants
may bear a single flower or many small flowers clustered
together. The fruits can be berries, drupes, capsules, or
schizocarps (dry fruits that split into segments of a single seed).
4. Rubiaceae, the madder family (order Gentianales)
of flowering plants, consisting of 611 genera with more
than 13,150 species of herbs, shrubs, and trees,
distributed primarily in tropical areas of the world.
Several species are of economic importance as sources
of useful chemicals, and a number are cultivated as
ornamentals.
5. Economically important products of the family Rubiaceae
include quinine, which is derived from the bark
of Cinchona species; coffee, from the seeds of Coffea species; ipecac,
from the roots of Carapichea ipecacuanha; gambier, a substance that is
used in tanning, from Uncaria gambir; and kratom (Mitragyna
speciosa), which is used in traditional medicine and recreationally as
a stimulant. Some trees in the family provide useful
timber. Common madder (Rubia tinctorum) was formerly cultivated
for the red dye obtained from its roots (alizarin); the roots
of crosswort (Crucianella) contain a red dye once used in medicines.