Biology Reference
In-Depth Information
•
Loasaceae (Keeler, 1981)
•
Meliaceae (Morellato & Oliveira, 1994)
•
Orchidaceae (Jaffe et al., 1989; Rico-Gray et al., 1989)
•
Oleaceae (Daumann, 1932)
•
Onagraceae (Keeler, 1979)
•
Rubiaceae (Bentley, 1977b; Faegri & van der Pijl, 1979)
•
Solanaceae (Davidson, 1988; Falcao et al., 2003)
•
Vitaceae (Sernander, 1906, after Schmid, 1988)
3.1.4
Symmetry
Structural nectaries are predominantly symmetrical structures. Effectively,
they show typically continuous arrangements, largely annular, which are ra-
dially symmetrical (e.g., ovarian nectaries in many Lamiales and Solanales,
petal nectaries in Malvales; Fig. 3A). They may also be composed of a num-
ber of independent glands that are evenly distributed in the flowers and show
radial symmetry as well (e.g., receptacular nectaries in many Malpighiales
and Geraniales).
Figure 3.
Nectary symmetry in floral diagrams. A, radial symmetry in
Nitraria retusa
(Ni-
trariaceae), modified from Decraene et al. (1996). B, bilateral symmetry in
Melianthus major
(Melianthaceae), modified from Decraene et al. (2001). Symbols:
black
= sepal (
outer
) and
petal (
inner
),
gray
= nectary,
white circle
= stamen,
central structure
= gynoecium (showing
number of carpels and ovules).
