Botrychium lunaria | Moonwort | Botrychium lunaria



Native status

Native species

Species Biology


  • Sporophyte plants grow to 5-28 cm, and produce spores from June to August on the fertile spike.
  • The small green plants may be hard to spot in longer grass.
  • Unlike other ferns the fronds (leaves) do not uncoil spirally. The frond is made up of two parts.
  • The shorted larger leaf blade is non-fertile and is pinnately divided into fan-like sections, of which there are 4-10 pairs.
  • The longer fertile spike is narrow and taller and is irregularly branched. It emerges from the non-fertile frond and is covered in spores in late summer.


Similar/related species:

There are only three species of ferns in the Ophioglossaceae family which occur in Ireland. Moonwort differs from the other two species (Adder’s tongue ferns) in that it has a pinnately dissected frond. Adder’s tongue fronds are entire and simple. 


Moonwort is a small fern which grows in well drained short grassy habitats on base-rich soils, open sunny places, heaths and dunes. Moonwort is widespread throughout Ireland but only in low numbers.  It can be difficult to find, even at known sites.

Both the perennial root of the sporophyte frond and the tiny gametophyte generation which lives deep in the soil associate with fungi species to survive. Plants die down at the end of summer and may not reappear for several years.

Threats faced

Moonwort habitats are under threat of being lost due to land abandonment, changes of use, and agricultural improvement.


World distribution(GBIF)

BSBI distribution map

Temporal change

Records submitted to Data Centre in 2021

The following map is interactive. If you would prefer to view it full screen then click here.

How can you help

If you have seen Moonwort or any of the species in the Irish Species Project, please fill out a recording form. It can be downloaded here, and you can also download the guidance document for detailed instructions (both also available at

You can also get in touch with your local BSBI Vice County Recorder via Maria Long, BSBI Irish Officer ( or contact her if you have any questions. 

Further information

One of eight species chosen for the Irish Species Project, a two year recording effort by the Irish division of the Botanical Society of Britain and Ireland (BSBI). All eight species are thought to be declining, at least in parts of their range.

Full list of eight species included in the Irish Species Project:

Moonwort (Botrychium lunaria), Cyperus Sedge (Carex pseudocyperus), Autumn Gentian (Gentianella amarella), Toothwort (Lathraea squamaria), Grass-of-Parnassus (Parnassia palustris), Cowslip (Primula veris), Common Wintergreen (Pyrola minor), Cranberry (Vaccinium oxycoccos)



Jermy C. and Camus J. (1991). The illustrated field guide to ferns and allied plants of the British Isles. London: Natural History Museum Publications

Merryweather J. and Hill M. (1995). The fern guide: an introductory guide to the ferns, clubmosses, quillworts and horsetails of the British Isles. Shrewsbury: Field Studies Council (Great Britain) 2nd ed.

Parnell J. and Curtis T. (2012) Webb’s An Irish Flora. Cork: Cork University Press 8th ed.

Preston C.D., Pearman D.A. and Dines T.D. (2002) New Atlas of the British and Irish Flora: An Atlas of the Vascular Plants of Britain, Ireland, the Isle of Man and the Channel Islands. Oxford: Oxford University Press

Stace C. (2010) New Flora of the British Isles. Cambridge; New York: Cambridge University Press 2010 3rd ed.