Gentianaceae is a family of of 105 genera and about 1600 species.
Etymology
The family takes its name from the genus
Gentiana, named after the Illyrian king
Gentius.
Distribution
Distribution is cosmopolitan.
Characteristics
The family consists of trees, shrubs and herbs showing a wide range of colours and floral patterns.
are
actinomorphic and bisexual with fused sepals and petals. The
are attached to the inside of the petals (epipetalous) and alternate with the corolla lobes. There is a glandular disk at the base of the gynoecium, and flowers have parietal placentation. The
inflorescence is cymose, with simple or complex cymes. The
are dehiscent septicidal capsules splitting into two halves, rarely some species have a berry. Seeds are small with copiously oily endosperms and a straight embryo. The habit varies from small
, pachycaul
to (usually)
, with ascending, erect or twining stems. Plants are usually rhizomatous. Leaves
opposite leaves, less often alternate or in some species whorled, simple in shape, with entire edges and bases
connation attached to the stem. Stipules are absent. Plants usually accumulate bitter
iridoid substances; bicollateral bundles are present. Ecologically, partial myco-heterotrophy is common among species in this family with a few genera such as
Voyria and
Voyriella lacking
chlorophyll and being fully myco-heterotrophic.
Ecology
Some of these plants have limited ranges and are protected under governmental oversight. For example,
Gentianella uliginosa (Dune Gentian), which occurs in some limited areas of
Wales and
Scotland, is a priority species under the Biodiversity Action Plan of the
United Kingdom.
Biogeographic history
Gentianaceae are distributed worldwide, but most species occur in temperate zones. According to Merckx et al.,
the
neotropics were an important area for the early diversification events in Gentianaceae, most of which occurring during the
Eocene. However, Pirie et al.
suggested that ancient
vicariance cannot be ruled out as an explanation for the early origins of
Exaceae across
Africa,
Madagascar and the Indian subcontinent unless a strong assumption is made about the maximum age of
Gentianales.
Uses
Economically, some species are cultivated
and many species yield bitter principles used medicinally and in flavorings.
Taxonomy
The family was first described by Antoine Laurent de Jussieu in 1789.
[
]
Tribes
Genera
105 genera are accepted.[
]
Phylogeny
External links
