With today’s entry, we conclude Katherine Van Dijk’s contributions as a work-study student for Botany Photo of the Day (though the official end date was actually two weeks ago). Thank you Katherine! For this entry, she writes:
To finish our series on white-flowered plants with medicinal properties, we have another wonderful contribution from 3Point141@Flickr. This photograph features Hylocereus costaricensis, commonly known as Costa Rica pitahaya, Costa Rica pitaya or Costa Rica night-blooming cactus. 3Point141@Flickr also has a 12 image set which captures the blooming of this magnificent species: Hylocereus costaricensis.
Pacific Island Ecosystems at Risk (PIER) describes Hylocereus costaricensis as a vigorous vine (up to 10cm in stem width), with white and yellow flowers sometimes exceeding 30cm in length. The site notes Hylocereus costaricensis as native to Costa Rica (costaricensis = “of Costa Rica”), Nicaragua and Panama, but unfortunately invasive in Hawaii.
Hylocereus and a few closely-related genera of cacti are well-known for their tasty dragon fruit or pitaya. The fruit of Hylocereus costaricensis is where medicinal uses are found. In Le Bellec, F. et al., 2006. Pitahaya (Hylocereus spp.): a new fruit crop, a market with a future (PDF). Fruits. 61:237-250, the authors note that dragonfruit is a significant source of antioxidants, including betalains. These compounds are currently being studied for medical efficacy, with some indications that they can be useful in preventing certain diseases (e.g., some forms of cancer). A different medicinal use for Hylocereus costaricensis was examined in a study which had results suggesting that an ethanol extract of the fruit pulp was successful in increasing sperm viability and production rate in mice (and could therefore presumably be used as a male fertility agent). See: Aziz, F. and M. Noor. 2010. Ethanol extract of dragon fruit and its effects on sperm quality and histology of the testes in mice. Biomedical Research. 21(2):126-130.