Biology Reference
In-Depth Information
on few individuals and few taxa per family. Even with some flaws or omis-
sions, it will help researchers and students to obtain quick information on the
amazing nectary diversity within the flowering plants.
Families in which no nectaries have been observed are indicated as such
here, to distinguish them from families for which no data were found. To
shorten the list of literature references for each family, recent papers or pa-
pers that include extensive literature on the subject were chosen. Most of this
information is also presented in the Appendix on page 122, but arranged ac-
cording to the different nectary types as defined above (see “Basic types of
floral nectaries”, on page 38); the families in which those nectary types were
reported are listed alphabetically and at least one publication is cited.
3.8.1
Early-branching lineages
Amborellaceae.
This monotypic dioecious family is the sister group of the
rest of the flowering plants (APG II, 2003). Its only species,
Amborella
trichopoda
, is endemic to New Caledonia and is pollinated by both insects
and wind. Pollen is the only reward for visitors in the absence of detectable
floral volatiles and nectar (Thien et al., 2003). Sporadically, free stigmatic
secretion was observed in female flowers, but no insects were observed to
consume it (Thien et al., 2003). These authors suggested that the presence of
a dry stigma would be the plesiomorphic condition for the basal angio-
sperms, and that a protonectar based on stigmatic secretions evolved inde-
pendently and along early diverging lineages (e.g., Annonaceae; Endress,
1990; Austrobaileyaceae; Endress, 1990; Chloranthaceae; Tosaki et al., 2001;
Magnoliaceae; Allain et al., 1999; Monimiaceae; Endress & Lorence, 1983;
Winteraceae; Gottsberger et al., 1980; Thien, 1980; Lloyd & Wells, 1992).
This protonectar produced by wet stigmas was believed to be a relictual
reward that evolved before the first nectar glands (Endress & Igersheim,
2000), although recent evidence calls into question whether the wet-type
stigma was the plesiomorphic condition in angiosperms (cf. Bernhardt et al.,
2003).
Nymphaeaceae.
The most primitive nectaries in the form of simple petal
nectaries are found in this family (Brown, 1938; Schneider & Jetel, 1982;
Vogel, 1998a; Schneider et al., 2003). As a whole, extant basal angiosperms
have bisexual, protogynous, fragrant, generalist flowers with no nectaries; in
addition, floral thermogenesis is widely distributed (Thien et al., 2000;
Endress, 2001b). Coleoptera and Diptera are the primary pollinators and
wind also seems to be important (Thien et al., 2000; Bernhardt et al., 2003;
but see Endress, 1990).
