Reusch, "Fitness-consequences of geitonogamous
selfing in a clonal marine angiosperm (Zostera marina)" Journal of Evolutionary Biology, vol.
In addition, qualitative differences in floral shape among clones was used to ensure that geitonogamous
pollinations were prevented.
These single-branch plants have no opportunity for between-branch geitonogamy and should, therefore, experience less geitonogamous
selfing than plants with multiple flowering branches, which had 5.4 [plus or minus] 4.8 other flowering branches (weighted mean [plus or minus] 1 SD), which bore a mean of 16.0 [plus or minus] 15.3 open flowers/d.
This may result in a limit to geitonogamous
pollen transfers and long distance pollen flow (Dressler 1981).
In the Faroes Islands, Hagerup (1951) indicated that species with large inflorescences tended to be geitonogamous
. However, Lloyd (1992) also pointed out that most cosexual SC species may be unable to avoid mixed mating--as would most likely occur in all of the SC hummingbird-pollinated species on the Juan Fernandez Islands.
pollinations can readily take place.
Although pollinator exclusion by bagging virtually eliminated fruit and seed production, geitonogamous
crosses (within plants, between flowers) produced normal fruit set [ILLUSTRATION FOR FIGURE 2 OMITTED].
One explanation for this pattern is that clipped plants may experience an increase in within-plant pollinator movement and associated geitonogamous
pollen transfer (see Juenger and Bergelson  for additional alternative hypotheses).
Pollinator behaviour often varies in different sized plants, with relatively more geitonogamous
pollinations in larger plants (Dudash 1991).
For those orchids in which small [delta] values lead to geitonogamous
pollination, the number of pollinaria removed may not be an accurate estimate of pollen export.
Among these genera, the mating system is known only for Bidens, where Sun and Ganders (1988) estimated that selfing occurred at a rate of 43% averaged over 15 populations of 11 species, due primarily to geitonogamous
matings of hermaphrodites.
A likely consequence of this foraging behavior is a high level of self-pollination (whether autogamous or geitonogamous
, Gomez and Zamora 1996), a common feature noted for other mass-flowering species (Augspurger 1980, Stephenson 1982, Frankie and Haber 1983, Harder and Barrett 1995, Snow et al.