Fern hybrids

Dr Leon Perrie from Te Papa explains why they named the cultivated hen and chickens fern Asplenium x lucrosum. He explains why this fern hybrid can reproduce while most other fern hybrids cannot.

Point of interest:

• Why does Leon say the hybrid hen and chickens fern has been profitable for the horticulture industry?

• Why are most fern hybrids ‘dead ends’?

DR LEON PERRIE

There’s 2 wild hen and chickens ferns in New Zealand. They have the scientific names Asplenium bulbiferum and Asplenium gracillimum. When we had worked out what these cultivated hen and chickens ferns were, we thought it was important to also give them their own name, so that they could be easily distinguished from the wild hen and chickens ferns. And we gave the cultivated hen and chickens ferns the name Asplenium lucrosum, and lucrosum is meaning ‘profitable’ or ‘gainful’ in Latin, and it’s an indication of how profitable these particular cultivated hen and chickens ferns have been for the horticultural industry, at least comparatively for ferns.

When we write the name, we write it Asplenium x lucrosum, and that x denotes that the plant is not a species in its own right. It has a name which makes it look like a species, but the x denotes that it’s a hybrid.

Most hybrids, particularly amongst ferns, are dead ends. They can’t reproduce because ferns, the spores that they try to form are abnormally formed. They will not give rise to… they cannot develop into gametophytes. In the case of the cultivated hen and chickens fern, it has inherited the ability to reproduce asexually from the true wild hen and chickens fern. So it has an out if you like, it can reproduce asexually. Most fern hybrids don’t have that ability to reproduce sexually, so they are dead ends.

Acknowledgement: Museum of New Zealand Te Papa Tongarewa