the hairs- are they hair or scales?
Does the undersides of the fronds have a layer of whitish powdery substance?
How many times are the fronds divided?

The hairs are definitely hairs, not scales.
The underside of the fronds don't have powder under them.
I'm not sure what you mean by "are the fronds divided."

I searched for photos on the internet but couldn't find any closeups. From a distance, the Australian Tree Fern and Hawaiian Hapu'u fern both look like mine. Do you know how to tell the difference?

Thanks!

Hapu'u tree ferns have hairs not scales. While the australian tree fern have scales. The sori (where the spore cases come out from) on the australian tree fern are located in the middle of the pinnae (frond divisions) while the sori of hapuu are located along the marigins of the pinnae. There are three common species of hapuu; Cibotium meziesii, C. glauca, and C. chamissoi. See the attatched link for photos of hapu'u ferns.

Here is a link that might be useful: Cibotium (UH Botany Native Plant Genre)

You've got a Cibotium, not an 'Australian' Cyathea cooperi tree fern - just as well, really, as they're an invasive species that colonises via wind-blown spores and out-competes the native Hawaiian tree ferns. The hairs you describe are pretty conclusive for a Cibotium ID, besides which nobody sells Cyathea cooperi in 20 gallon tubs. But they do pot up forested Cibotium trunklets in exactly this manner.

Although there are FIVE Hawaiian Cibotium variants that theoretically might come your way (four pure species, plus a naturally occuring hybrid of C.menziesii and C.chamissoi), the probability is that you have either C.glaucum or C.chamissoi - those two are the most common garden varieties. Precise identification between Cibotium species is fiendishly difficult without being an expert - all have waxy topsides to the fronds and varying degrees of powdery paleness underneath. Don't worry - care is identical as far as your garden conditions are concerned. Semi-bright location, very wind-sheltered, daily soaking of entire trunk length, regular mulching with fresh compost around the top of the tub, plus ultra-diluted fertiliser from time to time. Never let the tub sit in water - Cibotiums hate poor drainage and like their heavy watering regime to run straight through.

That's it! Warm, wet and well drained. Weak feed only.

Steve - Brighton, UK

Thank you so much for the information. I'm relieved to hear that I purchased a Hawaiian fern and not a competitive species that might harm native plants.

I'll be sure to give it wind protection and good drainage.

Thanks again!

Someone once told me that there are "kane" and "waihine" hapu'u ferns. The female kind had more delicate branches and more hairs, I think it was. This was years ago, is there any basis for that idea?

No basis whatsoever. Tree ferns don't come in male and female genders, just GENERA for the overall families (like Dicksonia, Cyathea and your Cibotium); and SPECIES which describe the individual types within a family (eg, Dicksonia antarctica, Cyathea cooperi, Cibotium glaucum, Cibotium chamissoi, etc). Some fern genera contain literally hundreds of different species within the family, others maybe one or two. Some genera have died out completely and all the species are regarded as extinct. Others are clinging on for dear life or are close to becoming endangered. The Cibotium family genus is kind of doing okay for now, although the general medium-term trend for all tropical rain forest and cloud forest habitats is grave indeed.

Hawaii has four accepted tree fern species: Cibotium glaucum, C.chamissoi, C.menziesii and C.nealiae. There is one other hybrid Cibotium variant that occurs naturally, but it's arguable whether this should count as a true 'fifth species' as it may not be able to reproduce and is instead simply the result of a one-generational cross between two of the other accredited species. Theoretically it can occur with every sporing by the contributing parent plants, it's just that the resulting hybrid offspring might not be truly reproductively viable itself, which is the standard criterion for assigning species status to new mutant strains. Like donkeys/asses and mules, I suppose. Even so, botanists are always revising the naming system and new species are regularly created from out of the ranks of previously unclassified plants. Maybe your inter-bred 'fifth' Hawaiian Cibotium will one day recieve the official stamp of 'new species'.

Unfortunately, all those Hawaiian names for Cibotium tree ferns - Hapu, Hapu'u, Man Fern, etc - are misleading, misapplied, and really only have a validity as folklore and perhaps when researching ethnobotany and the uses to which plants were put by ancient cultures. There's nothing about Cibotium in the general literature or on the internet that isn't pretty flaky, I'm afraid! Be very suspicious of anything you read about tree ferns in Hawaii, especially in the tourist press or gardening media. As for making sense of the diversity of flora and fauna around us, and transfering that knowledge across to conservation, gardening and serious horticulture, it's more reliable to use a rational and internationally understood naming system. It's impossible to look up stuff about plants, or talk about them accurately even within your own locality (let alone across the internet), unless the botanic names are applied. Forget that it originally comes from dead Latin and 19th century planthunters' names that we've all forgotten, and just see it as a reliable plant label that means the same thing anywhere on the planet, to expert or lay-person alike.

So, no male or female Cibotium tree ferns. Just different species, plus continuously mutating sub-species, local variants and hybrids. And lots of arguments by committees at international botanic conferences...

Steve - Brighton, Sussex Coast, UK

One can hope for all of them to have the same label, but I doubt it will happen. If a fern fancier goes into most any garden shop around here and asks for a hapu'u or even just a tree fern, the shop keepers or their clerks will instantly know where to direct the fern buyer to (unlike some shops I've heard about in the UK [smile]). However, if the fern fancier were to go into the same shop and ask for a "cibotium" of any variety the shop keepers would most likely look at them funny and say they don't have any.

Hmm, so if there aren't any male or female hapu'u ferns, then would you be able to identify the different cibotium species by the differences between one which was more delicate and the one that was more hairy?

There's clearly a cultural difference between the US and UK gardening scenes. The Latin botanical names are almost always used here in the gardening media, nursery catalogues, and in good plant shops. I can tell from the various US forums that it's done differently where you are. But how does anybody out of state (let alone in another country) know what you're talking about?

Can you identify different Cibotium species by hair characteristics alone? Not a hundred per cent reliably, but at least it's often a pointer that will help prompt the other diagnostic questions you'd be asking. Cibotium tree ferns are all hairy to a degree, and can vary a lot even within the same species, but Cibotium menziesii is the one that's likely to have the most pronounced coarse, dark hairs. Tufts even. Trouble is, you can't gaurantee it for every specimen growing in every habitat - there's considerable latitude. As a rule, the hairs on C.glaucum are softer, woollier and more gingery, as are the hairs on C.chamissoi. And the one that nobody ever sees, C.nealiae, that's also more likely to have a woolly ginger cladding around the curled up croziers and on the stipes. So, the most butch masculine Hapu'u would seem to be Cibotium menziesii.

Steve - Brighton, Sussex Coast, UK

Just came hunting after receiving a command from Auntie Elsie (75) to find her some new hapu'u as all hers were kane and she wants pretty wahine kind.

So OK there are no wahine kine hapu.

Her definition of the subject has nothing to do with butchiness, hair or the lack of hair, its all in the leaves. Kane kine have pretty leaves on top but as they age they get brown and ugly. Uh huh. Wahine kine have delicate pale green leaves from start to finish. Both kinds have babies (much giggling)

Her plants live in a permanent howling gale, which may have something to do with the brown leaves. I doubt they have ever been fertilized I did not see any spores under the leaves

Anyway the point of this post is: Are there any common unendangered species of hapu that might fit her definition of wahine fern? If so, might they be found in the Volvcano Village area, we are going up there to visit family this w/e. I would hate to grub up something endangered

I thank you

Woops! Auntie Elsie is obviously not your 'mum'. Sorry about that.Anyway, hope there's a happy resolution to the Hapu'u dilemma.

On the subject of which Cibotium hapu'u species has the most appealing colouration: Cibotium menziesii, the dark and hairy one, has a mid-green top side to the frond and a pale underside; Cibotium glaucum, with pale wispier stem hairs, has an almost blue-green topside and a VERY pronounced whitish underside...hence the name 'glaucum'; Cibotium chamissoi, is mid-green on top but altogether lacks the pale underside of the others. On all the species, the newly emerging fronds are a fresher green - but they soon darken with maturity and weathering.

At a quick first glance ALL the three commonly enountered Hawaiian Cibotium tree ferns look vaguely alike, but closer exmamination of the hairy/hairless frond stems, plus the paleness of the frond underside, is the obvious difference. There is an overall 'effect', too, that is different - but it's hard to put that into words and it's anyway a bit too subjective to offer as a hard and fast means of telling them apart.

But to summarise, I don't think it's very well grounded to discard or actively select one Hapu'u species over another simply on colour alone. The specific growing conditions of the particular location are more important.

Steve - Brighton, UK

Okay Steve, I'll bite-

(That's an americanism meaning that I'll ask the question you seem to be hoping for)

(insert drum roll here)
What are the specific growing conditions for each type of Cibotium?

A hui hou,
Cathy

P.S. Have you found a spore source from the Kauai treefern yet?

No, nothing to report yet on the search for the elusive dwarf Kauai tree fern, although there was a trail that went cold a couple of months ago (local policeman has them in his garden, but unfortunately no further news for a long time...).

The care regime for the various types of Cibotium is identical, so no special difficulties there. In other words: an organically rich compost mixture that is also particularly free-draining, plenty of watering, and restraint with chemicals and fertilizers. Very sheltered bright shade is the easiest aspect to cope with, although there is considerable latitude. As they grow on rapidly draining volcanic soils - often steeply sloped as well - the vital part is mimicking this moisture run-through while still keeping them permanently damp and humid. It's the hardest part for anybody like me in a non-Hawaiian climate (understatement of the year), but you folks have a head start in that regard!

Steve - Brighton, UK