Trochetia boutoniana flower and pollinator Blue-tailed Day Gecko (Phelsuma cepediana)

Trochetia - Trochetia spp.

Trochetia is a genus of flowering plants from the family Malvaceae (formerly in the Sterculiaceae, but this family is now usually subsumed in the Malvaceae). They are endemic to the Mascarene Islands.

The genus was first described by A.P. de Candolle in 1823, who named it in honour of French botanist Henri Dutrochet.

The genus Trochetia consists of scrubs or small trees, which can reach a height from two to eight metres. The hermaphroditic flowers are either white (T. triflora), pink (T. parviflora), or reddish orange (T. boutoniana). They are either single-standing, or grow in a cluster of three flowers. Some species have bell-shaped petals. All plants of this genus are imperiled due to the competition of invasive species, like the guavas from China but also by the destruction of introduced monkeys and rats. Five species occur on Mauritius and one on La Reunion. The habitat consists of humid forests with a high annual rainfall or mountainous slopes which are directed windwards.

Trochetia boutoniana also known by its native Mauritian name Boucle d'Oreille (in English: Earring tree, because of its bell-shaped look) is a shrub from the Trochetia genus endemic to Mauritius. Traditionally included in the family Sterculiaceae, it is included in the expanded Malvaceae in the APG and most subsequent systematics. It can reach a height up to 3 m. The leaves are oval shaped and due to its xerophyte adaptions it is leathery on the underparts. Also stipules are present. The petals are between 5 and 6 cm and they are growing asymmetric. They are bell-shaped and the coloring is dark red with a white background. The capsule is globular shaped and containts up to 10 black seeds. The flowering time is from June to October.

This plant is relatively rare because of its weak regeneration and due to introduced monkeys which feed from the blossom buds. The only occurrence are the slopes of Le Morne Brabant, Mauritius. Thanks to the efforts of botanist Joseph Gueho it was successfully germinate and grown in cultivation for the first time in 1973.

Trochetia boutoniana is the national flower of Mauritius since 1992 and it is often illustrated on stamps of Mauritius. It was named after French botanist Louis Bouton.

Plants from the genus Trochetia belong to the few plants worldwide that can produce coloured nectar. Some scientists, like the Danish ecologist Jens Olesen assume that this could be linked to bird species which have pollinated this plants in the past and are extinct today[1]. However, recent research has demonstrated that not only do endemic Phelsuma geckos pollinate some of the species, but that they actually prefer coloured over clear nectar. Hence, the 'mystery of the Mauritian coloured nectar can be considered at least partly solved now. Whether the nectar-feeding birds in Mauritius also react to the coloured nectar as a signal for floral reward remains to be seen.

The main pollinators of today are the Mauritius Olive White-eye (Zosterops chloronothos) and the Mauritius Grey White-eye (Zosterops borbonicus mauritianus), introduced honey bees, or geckos from the genus Phelsuma.

Recent research has shown that in the absence of the locally extinct Mauritius Olive White-eye, Trochetia blackburniana's main pollinator in the area of Le Petrin is the Blue-tailed Day Gecko (Phelsuma cepediana). Interestingly, the pollination efficiency of these geckos depend on the proximity to dense patches of Pandanus, which are a favourite microhabitat for the geckos - possibly because the spiky leaves of Pandanus protect them from their main predator, the Mauritius Kestrel (Falco punctatus).

Source:
http://en.wikipedia.org/wiki/Trochetia
http://en.wikipedia.org/wiki/Trochetia_boutoniana
http://news.nationalgeographic.com/news/2007/04/070423-gecko.html