Are you growing a hen & chickens fern at home? If so, chances are it’s a fake, unless you dug it out of the bush.
Hen & chickens ferns get their common name from their production of bulbils, or vegetative outgrowths, on the upperside of their fronds. These bulbils are the ‘chickens’ and the fronds are the mother ‘hen’. The bulbils can grow into new individuals, as a clone of their parent.
A bulbil, or ‘chicken’, of a hen & chickens fern. These are a vegetative, non-sexual mode of reproduction. Photo by Leon Perrie. (c) Leon Perrie, Wellington.
True hen & chickens fern – Asplenium bulbiferum – is found in the wild only in New Zealand.
Asplenium bulbiferum has closely-set frond segments, and usually many bulbils. Photo by Leon Perrie. (c) Leon Perrie, Wellington.
In addition to Asplenium bulbiferum, one other hen & chickens fern is native to New Zealand: Asplenium gracillimum. It is also native to Australia. Asplenium gracillimum is an allopolyploid of Asplenium bulbiferum and Asplenium hookerianum, being derived from hybridisation and a doubling of chromosome number.
Compared to Asplenium bulbiferum, Asplenium gracillimum has more diamond-shaped fronds, more space between its frond segments, and often only a few or even no bulbils. Photo by Leon Perrie. (c) Leon Perrie, Wellington.
Occasional plants of Asplenium gracillimum have very narrow frond segments. These have sometimes been incorrectly called Asplenium bulbiferum variety tripinnatum.
Asplenium gracillimum with narrow frond segments. These resemble the fertile fronds of Asplenium ×lucrosum (see below), but they can be distinguished by all of the fronds having narrow segments, rather than having both broad (when without spore-producing structures) and narrow (when with spore-producing structures) segments. Photo by Leon Perrie. (c) Leon Perrie, Wellington.
Most hen & chickens in cultivation are actually sterile hybrid plants properly called Asplenium ×lucrosum, despite usually being mislabelled by plant-sellers as Asplenium bulbiferum. Asplenium ×lucrosum is not native to New Zealand, but is a hybrid that arose in cultivation; its origin is a fascinating story.
Asplenium ×lucrosum and Asplenium bulbiferum are frequently confused, and not only by plant nurseries: most books and websites pertaining to illustrate Asplenium bulbiferum actually feature Asplenium ×lucrosum!
The false hen & chickens fern – Asplenium ×lucrosum – has dimorphic fronds (i.e., two different looking kinds of fronds) on the same individual. The fronds with spore-producing structures have much narrower frond segments than fronds without. This difference in form can even occur within a single frond if it has regions with and without spore-producing structures. Asplenium bulbiferum and Asplenium gracillimum do not have dimorphic fronds. Photo by Leon Perrie, Curator. (c) Museum of New Zealand Te Papa Tongarewa.
Close relatives of the Asplenium bulbiferum and Asplenium gracillimum hen & chickens ferns are Asplenium hookerianum and the cave spleenwort, Asplenium cimmeriorum.
The cave spleenwort, Asplenium cimmeriorum, is related to the hen & chickens ferns but doesn’t produce bulbils. It is found in limestone areas, including caves, around Waitomo and the north-west of the South Island. Photo by Leon Perrie, Curator. (c) Museum of New Zealand Te Papa Tongarewa.