Floral morphology and reproductive biology of Dendrobium jiajiangense (Orchidaceae) in Mt. Fotang, southwestern China

The relationships between floral morphology and the particular pollinator, flower shelter function and reproductive success as well as details of the breeding system of Dendrobium jiajiangense were investigated at Fotang Mountains in Jiajiang County, Sichuan Province, China. D. jiajiangense is pollinator-specific, being pollinated by Andrena parvula. There exists considerable mechanical fit between the floral morphology of D. jiajiangense and A. parvula. Importantly, A. parvula uses D. jiajiangense flowers as shelter both during rainy weather and at night during sunny weather. This significantly increase the pollination success of D. jiajiangens. D. jiajiangense is self-compatible but pollinator-dependent for fruit set. Fruit set of D. jiajiangens was 100% after hand-self-pollination, but seed viability was normally greatly reduced.