Blechnum penna-marina - Alpine Water Fern

Blechnum penna-marina is a hardy and creeping fern native to New Zealand and Australia, comfortable in moist to wet soils. This species forms a carpet of almost exclusively composed rosettes of linear sterile fronds, with a satin-like appearance and a beautiful dark green colour. They are evergreen, tough, and give a very clear appearance to the vegetation. This fern makes an excellent ground cover in wet humus-rich rockeries, in a sunny or very bright location.

Blechnum penna-marina is a plant of the family Blechnaceae, native to Oceania but also widespread in South America (Argentina, Chile) where it is commonly called Pinque or Punque. Its natural habitat consists mainly of wet, marshy, or waterlogged places, located in subalpine regions, where snow and frost are frequent.

This pretty little fern anchored on a creeping rhizome forms slightly loose rosettes of tough, narrow sterile fronds, divided into 2 rows of elongated pinnules, arranged like fish scales and of a dark green colour. These rosettes will not exceed 20cm (8in) in height, with a minimum span of 40 to 50cm (16 to 20in), much more over time. Then, in summer, the juvenile fronds appear in the centre of the clump, displaying a particularly bright green colour, tinged with pink and purple towards their tips. This species almost never produces fertile fronds and reproduces mainly vegetatively.

Less common than other species such as male and female ferns, this pretty creeping fern thrives on the edge of water points and sunny places where water constantly flows. It will easily settle in a damp and semi-shaded rockery, in soil with little limestone, or near a water point, in the company of Rodgersia, Petasites, silverweed, with its foot adorned with 'Chameleon' Houttuynia cordata. It is also a very romantic plant, perfect for filling the surroundings of a small waterfall or the mossy remains of a stone building, nestled in the hollow of the stones.