Biology Reference
In-Depth Information
Norris, 1941; Deng & Hu, 1995; Davies et al., 1996, 1998); they are related to
the filament bases, and the use of intra- and extrastaminal is imprecise here
because of the particular arrangement of the glands. The former Capparaceae,
which is now included in Brassicaceae, commonly has extrastaminal annular
receptacular nectaries between the sepals and petals, sometimes with three or
four appendages that are free or partly adnate to the calyx (Fahn, 1979;
Cronquist, 1981; Decraene et al., 2002; Kers, 2003); zygomorphic flowers
usually have a gland or nectary appendage (Kers, 2003). (See “Brassicaceae”
on page 47 for a detailed discussion.) For
Caricaceae
, it was observed that
staminate flowers produced nectar (Baker, 1976; Bawa, 1980); later, and
specifically in
Carica papaya
, Decraene and Smets (1999b) demonstrated
that nectaries of staminate flowers are located on the central rudimentary
pistil (not at the base of the stamens as supposed in earlier reports) and that
pistillate flowers produced no nectar but had stigmatic exudates.
Emblingi-
aceae
has a curved androgynophore with a unilateral receptacular nectary at
its base between the two petals (Cronquist, 1981), whereas in
Koeberlini-
aceae
the bases of the filaments are ventrally (i.e., the region facing the
gynoecium) nectariferous (Mehta & Moseley, 1981). On the other hand, in
Limnanthaceae
, nectaries are basal protrusions on the episepalous stamens,
and are dorsally located (Link, 1992c). In
Moringaceae
, the hypanthium is
nectariferous at its base, which surrounds the gynophore (Cronquist, 1981;
Decraene et al., 1998). In
Pentadiplandraceae
, there is an extrastaminal
receptacular annular nectary, protected by basal appendages of the petals
(Decraene, 2002).
Resedaceae
has extrastaminal receptacular nectaries, ex-
cept in
Oligomeris
(Cronquist, 1981). Nectaries are cylindrical or
infundibular and widen towards the adaxial side of the androgynophore to a
fleshy semi-lunate limb that produces nectar from a distinct gland on the
lower surface (Kubitzki, 2003). In
Salvadoraceae
, nectaries can be either
absent or present as nectar glands alternating with the stamens (Cronquist,
1981).
Tovariaceae
possesses low extrastaminal ring-like nectaries between
the filament bases (Fisel & Weberling, 1990; Decraene, 2002). In
Tropaeolaceae
, there is a nectariferous spur (Rachmilevitz & Fahn, 1975;
Cronquist, 1981; Decraene & Smets, 2001), which may be either small or
well-developed, and is formed by the sepals, although some authors (cf. De-
craene & Smets, 2001) consider it receptacular (axial or hypanthial). In some
species, the spur is showy and up to five times as long as the calyx lobes
(Bayer & Appel, 2003). Some of the nectar is produced by the unicellular
trichomes on the inner epidermis of the spur, but most originates from subepi-
dermal tissue (Rachmilevitz & Fahn, 1975; Fabbri & Valla, 1998).
Malvales.
The presence of nectaries is common in this order, except in the
families
Neuradaceae
, in which no nectaries were found in mature flowers
