Biology Reference
In-Depth Information
1981; Falcao et al., 2003). Three types of post-floral nectaries can be differ-
entiated, according to Schmid (1988):
•
Non-ovarian, persistent nectaries that continue to secrete nectar during fruit
development, i.e. they are indirectly related to the fruit.
•
Ovarian nectaries that directly continue to secrete nectar as ovaries develop
into fruits.
•
Fruit nectaries that are newly developed after pollination in growing fruits.
Post-floral nectaries seem to be comparatively less frequent than the re-
maining nectary types, but may have been overlooked. As an illustration, in
Croton sarcopetalus
(Euphorbiaceae; Freitas et al., 2001), only one of the
two nectary types present in female flowers functions as post-floral nectary.
More attention should be paid to taxa with persistent nectaries in field-
work (Smets, 1986), because more species may continue to secrete nectar
during stages of fruit development, and trends may be observed in some
families. The same consideration applies to families with extrafloral nectar-
ies located on persistent sepals, because they may continue to secrete nectar
throughout fruit development (e.g., Convolvulaceae; Keeler, 1980), as well
as extrafloral nectaries on the pedicels of buds and fruits (e.g., Bixaceae;
Bentley, 1977a). In some publications, the fruits are described as bearing
secreting structures, but as these are not specified as post-floral nectaries and
are not included in keywords, they are difficult to find.
According to the available literature, post-floral nectaries have been re-
ported in a small number of species from the following families:
•
Acanthaceae (Gracie, 1991)
•
Anacardiaceae (Wunnachit et al., 1992)
•
Annonaceae (Koptur, 1992)
•
Apiaceae (Szujko-Lacza, 1975)
•
Apocynaceae (Koptur, 1992)
•
Asparagaceae (Keeler, 1979)
•
Bignoniaceae (Elias & Gelband, 1975; Elias & Prance, 1978; Thomas &
Dave, 1992)
•
Brassicaceae (Delpino, 1898, after Schmid, 1988)
•
Buxaceae (Daumann, 1974)
•
Cactaceae (Davidson, 1988)
•
Convolvulaceae (Keeler, 1980)
•
Euphorbiaceae (Freitas et al., 2001)
•
Gesneriaceae (Davidson, 1988)
