4>8. Adiantum phyllitidis Group
A group of about ten species which includes Adiantum patens, and A. macrophyllum. They have simple fronds.
Most maidenhair ferns are terrestrial and a majority of them like lime, particularly the Adiantum raddianum and A. capillus..veneris groups that must have lime. Without it they will be very difficult to grow. They grow in damp usually fairly well..lit positions not so much in rainforest, but on the margins of rainforests, where there is a lower rainfall and more light. Ninety..nine percent of maidenhair ferns are terrestrial, one was seen in Papua New Guinea growing like an epiphyte up a trunk of a tree fern.
In cultivation, they need a well..drained, open soil with the addition of lime, good drainage and very good light. We grow our maidenhair ferns with a lot of light which makes them a little yellow in colour, but a stronger plant for the nursery trade. They like a draught..free position with humidity.
Pests that attack them are green or black aphids that are plentiful in the warmer months, mealy bug or woolly aphids, snails, slugs and also scale. Where there is an abundance of ants, there, will usually be an infestation of aphids or scale on your plants.
If your ferns are getting particularly untidy, has a lot of rot in the middle or diseased, cut it back and you get nice new growth. The new growth will initially come up more compact as it absorbs the nutrients stored up in the roots, but eventually it will end up at the desired height. This can be done at most times of the year, except in the middle of winter with the exception of tropical species or cultivars in our cool temperate climate.
Unfortunately, a lot of people let their ferns dry out, then they water to the extreme and drown them. When the foliage dies off, a lot of the roots die too and it becomes a grossly over..potted plant. These plants benefit most times by being potted back to a small..size pot. A nursery, potting mix is a basic mix of pine..- bark, coarse sand with fertilisers and lime added to it. Maidenhair ferns can survive much better from neglect if a compost mix is used.
In the nursery during the winter months, we can leave the watering for up to ten days but in summer the watering is done almost every day depending on the type of house they are in. The 175mm and 255mm pots are watered by a drip..system, and the 125mrn pots and our personal collection are hand..watered.
There are a lot of cultivars in cultivation, probably more than there are species. In my book, I cover nearly one hundred of them, as they hybridise very easily. Over the years, we have grown many different maidenhair ferns, and found different forms popping up in our fem nursery just by chance.
Two that came up in the nursery were from the Adiantum raddianum group. My wife, Lorraine was watering the ferns one day and noticed a A, fragrans plant with an unusual frond amongst them, The plant was set aside until it sent up a fertile frond and the spore from this reproduced true, and we soon had hundreds of plants. This cultivar was new and I named it A. raddianum cv. Lorraine.
The other one my mother (Gladys) found. She often came and dug up all the maidenhair ferns that came up on the nursery benches, took them home and potted them up for family avid friends. One day, 1 was visiting her and asked where she had got this unusual maidenhair fern from, and told me it had come from our nursery. Again, it was a new cultivar and 1 named it A. raddianum cv. Gladys Glory after her. To experiment with hybridising, pick the cultivars you want to cross and sow one cultivar over the other one. We had a lot of success using this method with Aspleniums.
There were not many specialist books on this subject, when my book Maidenhair Ferns in cultivation was written. The only literature available was Barbara Joe Hoshizaki's papers (1970) The Genus Adiantum in Cultivation, and they had a wealth of information in them, covering the species, cultivars and cultivation in the United States of America. It look me two years of research to prepare my book.
My goal was to record the origin as far as 1 could of the Australian cultivars before this information was lost, new cultivars have since been developed.
Finally I could not have completed this book without the assistance given to me by Barbara Joe Hoshizaki.
Adiantum aethiopicum (Common maidenhair)
Stipe: slender, reddish brown to almost black, smooth and polished, near the base a few pale papery scales
Adiantum capillus-veneris (Dainty maidenhair)Rhizome: creeping, short, relatively coarse, covered with narrow brown scales with attenuate tips.
Fronds: clustered, length to 50 cms.
Stipe: long, slender dark brown to purplish-black, smooth, polished, scales near base light brown and shiny.
Lamina: mid-green, membranous, ovate, 2 -3 pinnate, glabrous.
Rachis: very dark, slender.
Pinnules: fine almost centrally attached stalks, 7 -15 mm wide, slightly asymmetrical with wedge shaped bases and rounded outer edges, often with deep and irregular lobes, finely toothed; veins numerous, repeatedly forked, free.
Sori: 4 - 7, large, at apex of lobes causing them to appear truncate.
Indusium: false, oblong-oval.
Adiantum formosum (Black stem or Giant maidenhair)
Rhizome: creeping, coarse, covered with scales.
Adiantum hispidulum (Rough maidenhair)
Rhizome: creeping but relatively short and coarse, covered with dark brownn scales.
Adiantum diaphanum (Filmy maidenhair)
Rhizome: short, semi-erect, covered with reddish brown scales, fibrous roots with numerous small tuber-like swellings.