Abstract Detail

Anatomy and Morphology

Bogler, David [1], Davis, Marshay [2].

Observations on Flowers of Nesocodon mauritianus (Campanulaceae), a rare, gecko-pollinated endemic from Mauritius.

Mauritius is an island in the Indian Ocean east of Madagascar. It is home to the endangered species Nesocodon maritianus, Campanulaceae. Small populations were discovered growing on a cliff near a waterfall. Seeds were collected in the 1980s by Peter Wyse Jackson and the species is now grown in greenhouses around the world. This species differs from related species in producing only a single flower instead of a raceme. It is also unusual in that it produces orangish-red colored nectar. The color and pattern of the orange droplets of nectar on a light blue corolla closely resemble the spots on the back of an associated gecko, (Phelsuma ornata), which is believed to be involved in pollination. Although it has been demonstrated that the gecko is attracted to orange droplets more than clear ones, it is not clear how pollination is accomplished. The purpose of this study was to learn about floral and reproductive biology of N. mauritianus by careful observation of floral morphology of N. mauritianus. The structure and sequence of flowering was compared with related species at the Missouri Botanical Garden (Campanula trachelium, Platycodon grandiflorus, Lobelia cardinalis and L. siphilitica. Flowers are dichogamous, with distinct male and female phases. In the male phase the anthers dehisce early, and pollen is shed on the developing style. In the female the style and closed stigma push through the anthers and the stigma opens. Self-fertilization in the same flower is unlikely, suggesting N. mauritianus is primarily outcrossing. The pollen of N. mauritianus is minutely verrucose-spiny, much like Campanula and Platylcodon species, but unlike pollen of Lobelia spp. Nectar sugar concentration was measured using a refractometer. Nesocodon mauritianus had the lowest sugar concentration (6%), while Lobelia cardinialis had the highest (17%). Our data indicate that Nesocodon mauritianus flowers most closely resemble Platycodon grandiflorus in appearance, sequence of floral development, nectar concentration, and pollen. Further research on the population genetics of N. mauritianus to determine the inbreeding coefficient is the next step.

1 - Missouri Botanical Garden, 4344 Shaw Blvd, St. Louis, MO, 63110, United States
2 - Harris-Stowe State University, Math and Natural Science, 3026 Laclede Ave, St. Louis, MO, 63103, USA

flower morphology
pollination biology
Floral Nectary

Presentation Type: Poster This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PAM014
Abstract ID:1044
Candidate for Awards:None

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