Glossary of Indoor Fern Terms


Bark compost

Ready-made compost containing bark humus as the main component. A certain nutrient content and pH values of 5.5-7 should be provided by this type of compost. There are many different types and ferns should be given a nutrient-poor grade.

Bark humus

Chopped, shredded bark, mainly from conifers, which is used in proportions of 30-60 per cent as a component of compost.

Coarse bark humus improves the ventilation of compost and is, therefore, particularly suitable for epiphytic ferns.


Small immature bulbs or buds that form on shoots or on leaves. Small offset plantlets may form from these.

ferns growing in an aquariumEpiphyte

A way of living that involves plants (epiphytes) growing on trees without using them for food so they are not parasitic.


Fruitful; in the case of ferns this means they form spores.


Part of a multi-feathered leaf.


The occurrence of two different types of leaves on one plant. In many ferns both fertile and sterile fronds are formed. The sterile fronds usually have shorter stalks and possess broader surfaces. The fertile ones have longer stalks, possess narrower pinnae and stand stiffly upright which is advantageous for the distribution of spores.


A thin layer of skin which covers and protects the developing sori of many ferns. The shape of the indusium is characteristic of individual genera and species. Where these have been replaced by leaf edges which curl backwards, they are called pseudo-indusium.

Leaf rib

The central stem of a feathered leaf.

Peat compost

Ready-made compost consisting of bog peat with an established nutrient content and a pH value of 5-6. Nutrient-poor peat compost is suitable for ferns.

PH factor

Degree of acidity. For most indoor ferns a medium acid pH compost of 5-6 will be favourable.


Part of the sexual generation of ferns. A flat, often heart-shaped prothallium develops from the fern spore.


Thickened shoots which develop horizontally, usually underground, as storage or reproduction organs. In some fern species, like Davallia, they also grow above ground.

Sorus (plural sori)

Groups of spores which form different shapes. They form on the undersides of fern fronds.

Sporangium (plural sporangia)

Capsules with stalks in which the spores develop and out of which they are catapulted when ripe.


Single-cell propagation units which form on the undersides of the fern fronds.

Standard compost

Ready-made compost made up of 60-80 per cent by volume of bog peat and 20-40 per cent by volume of loam with a varying nutrient content. The standard types possess a pH factor of 5.5-6.5 The types containing a low-dosage controlled-release fertilizer are suitable for ferns.

Sterile parts

Non-fertile parts which do not produce spores.


Growing on the ground.


Multi-coloured leaves; for example, green and white, green and yellow and green and red.

23. May 2011 by Dave Pinkney
Categories: Glossary, House Plants, Indoor Ferns | Tags: , , , | Comments Off on Glossary of Indoor Fern Terms


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