Here are two striking and (I think) attractive Blechnum hard
ferns. Nigrum is Latin for black. Colenso’s hard fern is named
after William Colenso – printer, missionary, politician, and
naturalist – altogether a very extraordinary person. Biography
of William Colenso. The “hard” part of the name comes, I
presume, from the texture of the frond; most species are fairly
rough and almost leathery. Both Colenso’s hard fern and the
black hard fern are found in wet, shaded, and usually cold
habitats. The above photographs were taken along the Mangahao
Makahike Track near Levin. Although at a relatively low
altitude, it nevertheless provides good conditions for these
species. Blechnum is one of the biggest fern genera in New
Zealand, with 18 indigenous species. They are easily recognised
because almost all have dimorphic (different looking) fertile
and sterile fronds. The fertile fronds, which make the spores ,
have much thinner segments and are black or nearly so. They are
also often held up above the sterile fronds.