A nod of appreciation to Qamar, aka S.Q. Mehdi@Flickr of Lahore, Pakistan for contributing today’s photographs (original image 1 | original image 2 | Botany Photo of the Day Flickr Group Pool). Thank you!
Despite these photographs of flowers in Pakistan, citron rain-lily or citron zephyrlily is native to the Americas — somewhere. The USDA’s Germplasm Resources Information Network says it all: “native range obscure“. As mentioned in the Flora of North America, it first arrived in the hands of European plant taxonomists via a secondhand collection believed to be from Guyana (in northeast South America), but there is significant uncertainty about whether it is indeed native to Guyana. Since it is capable of rapidly reproducing from a single plant (more on this later) and it is tolerant of seaside conditions, this species establishes quickly when introduced into new tropical / subtropical areas due to human transport. Hence, it is found in coastal areas of southeastern USA, Central America, South America, Hawaii, tropical Africa, the Malay Peninsula and southeast Asia.
Leaving aside the question of where this species is native to (possibly the Yucatan Peninsula?), a botanical tidbit of special note about Zephyranthes citrina is its tendency to use asexual reproduction: the species is apomictic. This means it can, and often does, produce seeds without fertilization. The offspring are then genetically identical to the parent plant. Despite giving up the evolutionary advantages of sexual reproduction when this mode of gene transfer is used, many benefits are realized. For example, when an individual plant is well-suited to a particular environment, it can rapidly produce many similar individuals that presumably will also prosper — on its own. As it applies to Zephyranthes citrina, this means that the transport of a single seed or plant to a new area suitable for growth can result in the rapid establishment of new colonies of the species. For the story of another successful apomictic species, research Taraxacum officinale. I should note: most, if not all, apomictic species are facultatively apomictic, meaning they also use sexual reproduction on occasion.
Another species of Zephyranthes was previously featured on BPotD: Zephyranthes fosteri.
Beginning Monday, I’ll be doing a series on narrow-range endemic plants of the Pacific Northwest of North America.