Systematics of the economically important genus Elaeagia in the coffe family (Rubiaceae)
Rubiaceae are one of the largest families of flowering plants with approximately
650 genera and 13,000 species worldwide, and about 220 genera and 5,000 species
in the Neotropics. Many Rubiaceae
are economically important including coffee (Coffea arabica) and the Quina tree (Cinchona succiruba, C. lancifolia) whose bark contains
alkaloids that are used to cure malaria. The family also include many
ornamental plants such as the much appreciated Gardenias (Gardenia jasminoides). Considering its
economic importance, the systematic classification and evolution of this family
has received remarkably little attention compared to other large families like
the Asteraceae and the Orchidaceae.
Elaeagia Weddell is a relatively small New
World genus of Rubiaceae that includes
around 15 species. It comprises small to medium size trees in tropical
mountains mainly between 500 m and 1500 m elevation. Elaeagia differs from all other Rubiaceae by secreting a greenish resin from the stipules
of the foliar buds. This resin is known as “lacquer” and has the appearance of
small, sticky pellets that may be handpicked from the young shoots of the
trees. From immemorial times, artisans in San Juan de Pasto,
Nariño-Colombia, have applied a specialized technique
covering their famous handicrafts with the “lacquer” resin of Elaeagia pastoense L.
E. Mora, known as “Barniz de Pasto.”
In order to obtain “Barniz de Pasto,”
the artisans first heat the resin balls to form a malleable mass. Afterwards,
the resin is stretched and cleaned, and may be coloured. The resin is
manipulated until a very thin, sticky layer is formed, and this is spread at
the surface of the material the artisan is working with, which could be wood,
metal or glass. Overall this treatment corresponds to wrapping handicrafts with
a coloured “cloth” that gives them a truly attractive appearance.
Elaeagia occur in most mountain forests in the Americas. It
ranges from southern Mexico,
through Central America, along the Andes south to Bolivia. It is also found at a
number of West Indian islands including Cuba. Botanists have described more
than 20 different species of Elaeagia, but the true number is unknown, and can only
be determined by studying and comparing collections from all parts of its
range. Fortunately, the number of Elaeagia collections has risen steadily during recent
decades facilitating that this work now can be done.
The objective of the present project is
to elaborate a detailed taxonomic and phylogenetic
study of the genus Elaeagia.
This study should help to determine if other species of Elaeagia show similar properties
as E. pastoense,
and consequently may be used in similar ways. The uses of E. pastoense and other Elaeagia species
will be valued economically, socially and ecologically.
Participant Carla Maldonado, supervised
by Finn Borchsenius, Henrik Balslev & Mónica Moraes