Breeding system and pollination by mimicry of the orchid Tolumnia guibertiana in Western Cuba

Abstract

The mimicry of malpighiaceous oil-flowers appears to be a recurrent pollination strategy among many orchids of the subtribe Oncidiinae. These two plant groups are mainly pollinated by oil-gathering bees, which also specialize in pollen collection by buzzing. In the present study, the floral ecology of the rewardless orchid Tolumnia guibertiana (Oncidiinae) was studied for the first time. The orchid was self-incompatible and completely dependent on oil-gathering female bees (Centris poecila) for fruit production. This bee species was also the pollinator of two other yellow-flowered plants in the area: the pollen and oil producing Stigmaphyllon diversifolium (Malpighiaceae) and the polliniferous and buzzing-pollinated Ouratea agrophylla (Ochnaceae). To evaluate whether this system is a case of mimetism, we observed pollinator visits to flowers of the three plant species and compared the floral morphometrics of these flowers. The behavior, preferences and movement patterns of Centris bees among these plants, as well as the morphological data, suggest that, as previously thought, flowers of T. guibertiana mimic the Malpighiaceae S. diversifolium. However, orchid pollination in one of the studied populations appears to depend also on the presence of O. agrophylla. Moreover, at the two studied populations, male and female pollination successes of T. guibertiana were not affected by its own floral display, and did not differ between populations. The results are discussed in relation to the behavior and preferences of Centris bees, as well as the differential presence and influence of each of the two floral models.

<em>Zygostates alleniana</em> (Orchidaceae: Epidendroideae: Cymbidieae: Oncidiinae): estructura floral relacionada con la polinización

“…Dentro de Oncidiinae hay especies que poseen flores miméticas a las de Malpighiaceae (Powell & et al, 2003;Vale & al., 2011;Papadopulos & al., 2013), las cuales carecen de elaióforos y atraen a los visitantes por engaño. Otras especies, cuyas flores también son semejantes a las Malpighiaceae, poseen elaióforos y ofrecen recompensa a sus polinizadores.…”

Elucidating cryptic sympatric speciation in terrestrial orchids

“…Stelis Sw., Polystachya Hook., Cleistes Rich.). Furthermore, parallelisms in flower characteristics involving distinct genera within Orchidaceae and between orchids and other plant families frequently occur (Vale et al, 2011;Pansarin et al, 2017).…”

Distribution, habitat disturbance and pollination of the endangered orchidBroughtonia cubensis(Epidendrae: Laeliinae)

“…it is pollinated by two small pollinators with quite different nesting requirements), it may be able to survive local extirpation of one or more pollinator species. Deceptive orchids usually rely on the abundance of floral rewards of other plant species (Internicola et al, 2007;Carmona-Díaz & García-Franco, 2009;Vale et al, 2011b). In the case of B. cubensis, the role of T. corymbosa and C. gerascanthus as possible model plants sensu Dafni (1984), magnet plants sensu Johnson et al (2003) or simply as co-occurring nectariferous species sensu Internicola et al (2007) and Peter & Johnson (2008) could be a key element in the management of this orchid in situ.…”