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Detailed information sheet

Click on the photos for a larger image.

Botanical name :
Nephrolepis cordifolia
Family :
Davalliaceae (ground fern) family
Common name :
tuber ladder fern 
Also known as :
sword fern, Boston fern, tuber sword fern  
Where is it originally
from? :
What does it look like? :
Terrestrial or epiphytic fern to 1 m with small, erect, scaly rhizomes producing many long runners and round, 1-3 cm hairy potato-like tubers. Fronds (40-100 x 5-8 cm) are erect or arching when long, with serrated, divided leaflets.
Are there any similar
species? :
The rare native ladder fern (Nephrolepis novae-zelandii) is similar, but fronds only grow to 65 cm and it has no tubers. Indoor ferns N. exaltata, N. maasii (both also called Boston fern) are not known to be weedy and have wider, softer fronds and no tubers.
Why is it weedy? :
Spreads by spores, runners and tubers, and forms dense, long-lived patches which are often large. Grows in the damp or dry, on the ground or in trees, in the open or the shade, in most soil types and in hot to moderately cool temperatures. 
How does it spread? :
Spore spread is probably minor, but runners and tubers are spread in dumped vegetation and soil, and occasionally water. Gardens, waste areas, tracks, rock outcrops, banks, streamsides are all sources of new infestations. 
What damage does it do? :
Crowds out groundcovers, shrubs and other ferns, and can contribute to streamside erosion. 
Which habitats is
it likely to invade? :
Disturbed bush and shrubland, fernland, tussockland, coastal forest, streamsides, and gumlands. 
What can I do to get
rid of it? :
Easy to kill.
1. Pull out, Leave on site to rot down. Dispose of tubers and runners at a refuse transfer station, burn or bury. 
2. Spray: metsulfuron-methyl 600g/kg (1g/10L).  Leave sprayed sites 3-4 months to allow herbicide to translocate to tubers before clearing or replanting. 
What can I do to
stop it coming back? :
Runners and tubers resprout if not disposed of carefully.

Description:Nephrolepis cordifolia.Photo:by R.Smart

Description:Tuber ladder fern clumps.Photo:C.Lewis

Description:Tuber ladder fern infestation.Photo:C.Lewis


For more detailed botanical descriptions of weed species, check out the Plant Conservation Network's website at http://www.nzpcn.org.nz/exotic_plant_life_and_weeds/index.asp

Click here for Herbicides and Trade names

*The chemical control methods in this manual were devised by Department of Conservation staff for Department of Conservation operations and should not be used as a substitute for the pesticide manufacturer's label instructions. The Department of Conservation takes no responsibility for any liability or damage to any person, property or thing which may occur as a result of the use of any pesticide in accordance with the chemical control methods contained on this website.


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