The large, solitary flowers are produced from cordiate leaf axils. Leaves can be up to 25 cm wide. Flowers are heart shaped: 10–20 cm wide and have tails that are up to 60 cm (24 in). The flower is green/white with purple/brown veins. The centre of the flower is darker coloured, which attracts pollinators along with a distinctive odour to its reproductive elements. The flower has three sections, utricle, tube and limb, characteristic to all Aristolochiaceae.
The plant is native to the Caribbean and Central America, and has been introduced to Florida in the United States as an attractor of butterflies. It is found in tropical forests near streams and gullies. A. grandiflora is pollinated by breeding flies attracted by the odour of the flower. Flies travel down the tubular part of the flower to the utricle where the reproductive organs are found. The tube is lined with trichomes that direct the fly down to the utricle and prevent the fly from moving out.
Reproduction occurs in three main phases. In the first phase, the fly carrying pollen from other flowers pollinates the carpel. During the second phase, the stamen matures releasing pollen on the fly. This phase lasts one day. While trapped inside the flower, the fly eats nectar produced along the walls of the utricle. The trichomes then are signalled to wither, allowing the fly to escape. The entire reproductive process lasts two days before flower senescences and abscises in the third phase.
A. grandiflora has been used for ornamental purposes, as a food source, and in traditional medicine. It is a food source for swallowtail butterfly larvae. These butterflies become unpalatable to predators when they consume the terpenes in this plant. The use of this plant poses a risk as it contains the toxin aristolochic acid which is carcinogenic. The USDA has banned all products containing this compound. A. grandiflora contains many different alkaloids (bisbenzylisoquinolinic and 8-benzylberberinic), which aid in chemical defences against insects and plant microbes.
This post is part of the Floral Friday Fotos meme.