categoryZFerns Ferns List 

RUSTY-BACK FERN

Asplenium ceterach

(Formerly: Ceterach Officinarum, but on BSBI website as Asplenium ceterach)
Spleenwort [Aspleniaceae]

Spores:
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Fronds:
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category
category8Ferns
status
statusZnative

1st Sept 2011, Capel Soar Y Mynydd, Llyn Brianne, Elenwydd Wilderness. Photo: © RWD
Showing relationship in size between the smaller and similar Maidenhair Spleenwort and Rusty-back. The leaflets on Rusty-back are alternate whilst those of Maidenhair Spleenwort are opposite. Fronds radiate outwards from a central point.


1st Sept 2011, Capel Soar Y Mynydd, Llyn Brianne, Elenwydd Wilderness. Photo: © RWD
Presers to find a niche in walls, either limestone dry stone walls, or walls with mortar, for it likes alkaline environments. Note the rusty backs of those fronds that have curled over.


1st Sept 2011, Capel Soar Y Mynydd, Llyn Brianne, Elenwydd Wilderness. Photo: © RWD
Fronds have a central backbone (rachis) that runs the length, which leaflets overlap alternately, creating a zig-zag of almost constant width of green. Initial leafless stem is short.


1st Sept 2011, Capel Soar Y Mynydd, Llyn Brianne, Elenwydd Wilderness. Photo: © RWD
A fringe of white scales borders each leaflet.


1st Sept 2011, Capel Soar Y Mynydd, Llyn Brianne, Elenwydd Wilderness. Photo: © RWD
A few white scales also inhabit the top surface.


1st Sept 2011, Capel Soar Y Mynydd, Llyn Brianne, Elenwydd Wilderness. Photo: © RWD
The scales are pointed, and will eventually go reddish-brown.


1st Sept 2011, Capel Soar Y Mynydd, Llyn Brianne, Elenwydd Wilderness. Photo: © RWD
The underside is covered both in brown spores and brown scales.


1st Sept 2011, Capel Soar Y Mynydd, Llyn Brianne, Elenwydd Wilderness. Photo: © RWD
The brown scales on the underside give the plant its name, rusty-back.


Some similarities to : Wall-rue (but that has leaflets that are rounder and in three's)and Maidenhair Spleenwort (but that has leaflets that are in opposite pairs and is more delicate than Rusty-back) and to Green Spleenwort (which although it has in alternate leaflets, they are attached to the mid-rib at a point rather than along their length) or the Polypodys (but they are much larger). All these lack the rusty-brown scales on the back of Rusty-back.

Uniquely identifiable characteristics

Distinguishing Feature : The rusty-coloured scales on the back.

There is a very definite preference for Rusty-back in the South-West of the UK and a definite avoidance of the North-East. It prefers lime habitats, either cracks in limestone dry-stone walls, or mortar cracks in walls, but also grows in limy rocks.


  Asplenium ceterach  ⇐ Global Aspect ⇒ Aspleniaceae  

Distribution
 family8Spleenwort family8Aspleniaceae

 BSBI maps
genus8Asplenium
Asplenium
(Spleenworts)

RUSTY-BACK FERN

Asplenium ceterach

(Formerly: Ceterach Officinarum, but on BSBI website as Asplenium ceterach!)
Spleenwort [Aspleniaceae]

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