Biology Reference
In-Depth Information
(Decraene & Smets, 1995), and
Bixaceae
, which has pollen as reward (Pop-
pendieck, 2003a, b). The other families have receptacular nectaries (intra- or
extrastaminal), more rarely on calyx or corolla.
Cistaceae
bears an annular
intrastaminal receptacular nectary, which is many-lobed (Fahn, 1979; Cron-
quist, 1981; Manetas & Petropoulou, 2000). A few papers indicate that some
Dipterocarpaceae
species have nectaries and produce nectar (Ghazoul, 1997;
Harrison et al., 2005), but do not specify the precise location of the nectarifer-
ous tissue; on the other hand, some authors have not observed nectaries
(Ashton, 2003). In the broadly circumscribed
Malvaceae
(including Bomba-
coideae, Byttnerioideae, Dombeyoideae, Grewioideae, Helicterioideae, Malvoi-
deae, Sterculioideae, and Tilioideae), the unusual floral nectaries, composed of
densely packed, multicellular, glandular trichomes, have been identified as a
synapomorphy (Judd & Manchester, 1997; Vogel, 2000). As there are some
nectarless taxa in this family, Vogel (2000) suggested that this loss could be
either secondary or a plesiomorphy, considering the basal position of the
mostly nectarless taxa (Grewioideae, Byttnerioideae). Trichomes are generally
limited to the calyx adaxial surface, but they can also occur on the corolla or
the androgynophore (Donato, 1991; Vogel, 2000; Leitao et al., 2005); this
barely investigated topographical diversity may provide useful taxonomic
characters (Vogel, 2000). The nectar is frequently directly accessible by pol-
linators because of the flower shape and the way in which the petals are
separated, but it can have a secondary presentation (Vogel, 2000). In
Muntingiaceae
, there is an intrastaminal receptacular nectary as part of the
broad receptacle of the flower, and nectar is retained by short hairs surround-
ing the nectary (Bawa & Webb, 1983). In
Sarcolaenaceae
, there is an
extrastaminal receptacular annular ring considered nectariferous, which
is cupular or deeply quinque-partite (Cronquist, 1981; Bayer, 2003).
Sphaerosepalaceae
possesses a short gynophore that bears an intrastaminal
receptacular nectary towards its apex (Horn, 2004). In
Thymelaeaceae
, the
nectaries may be absent (in Octolepidoideae), but when present, they are
intrastaminal receptacular, either consisting of separate scales, or a cup-
or cuff-shaped ring (Cronquist, 1981; Herber, 2003; Cornara et al., 2005;
Bandera & Traveset, 2006).
Sapindales.
A conspicuous receptacular nectary (Cronquist, 1981) is typical
and according to Gadek et al. (1996), is a potentially important morphological
synapomorphy for the order.
Anacardiaceae
has intrastaminal receptacular
nectaries, generally well-developed and sometimes transformed into short
gynophores (Cronquist, 1981; Wannan & Quinn, 1991; Gallant et al., 1998);
in
Anacardium occidentale
, nectariferous trichomes were reported on the
corolla base (Wunnachit et al., 1992).
Biebersteiniaceae
nectaries are sepa-
rate extrastaminal nectary glands at the base of the antisepalous stamens,
