Category Archives: Ferns

Help with floating fern

I’ve recently learnt that the introduced Azolla pinnata (ferny azolla) has been found in the Wellington region. I’m interested in its distribution and would be grateful for help in looking for more. Azolla plants are fairly easy to spot: look for a red plant covering still bodies of water.

Azolla plants often become red in full sunlight, and they can become so abundant that they carpet ponds, drains, and other still bodies of water. This is Azolla rubra in a pond on Mana Island, Wellington. Photo Leon Perrie. © Te Papa.

Azolla are ferns, believe it or not! They are free floating, and while individual plants are only a few centimetres across, they can proliferate in good conditions to ‘carpet’ large areas of water surfaces.

There are two species in New Zealand: the native Azolla rubra (Pacific azolla, previously known as Azolla filiculoides); and the exotic Azolla pinnata, which is an introduction from the tropics.

Azolla pinnata has largely replaced the native Azolla rubra in the northern North Island. It is therefore a concern that A. pinnata was found near Waikanae in recent weeks, after being found near Whanganui a few years ago. It seems it is continuing to spread south.

The introduced Azolla pinnata has very regular branching. Plants can be red or green depending on whether they are in the open or shade, respectively. The green ovals are Lemna duckweed (a flowering plant). Photo Leon Perrie. © Leon Perrie.

The branching of the native Azolla rubra is irregular. Photo Leon Perrie. © Te Papa.

Can you help please?

I would like to better document the distribution of the two Azolla species in New Zealand, and particularly the spread of the introduced A. pinnata. The southern North Island is the primary interest, but anything that adds to what we already know would be useful (see the link to the map below).

Map of Te Papa’s collections of Azolla.

If you see Azolla (either species), you could post a comment or send me an email. If you have landowner permission, you could make a collection for possible addition to Te Papa’s specimens: post me 20-30 plants enclosed within a watertight plastic bag, with locality details, and your contact details. My address is: Leon Perrie, Te Papa, PO Box 467, Wellington 6011.

Thanks very much.

Where to find new species?

Where would you go to find a new species?

Perhaps somewhere remote and little-visited, especially if it is ecologically unusual – New Caledonia maybe

Well, instead, how about inside Te Papa’s collections, because that’s where I first discovered a new species of Gleichenia tangle fern.

Biodiversity-treasure – inside one of Te Papa’s two botany collection stores. Te Papa has over 250 000 dried plant specimens. Copyright Te Papa.

A lot of biodiversity remains to be documented, particularly amongst smaller plants and animals, and micro-organisms.  But in a well-explored country like New Zealand, it is uncommon to find a clearly distinct new species of fern or seed plant.  Instead, taxonomists like myself spend a lot of time with statistical and/or genetic analyses trying to determine whether similar things are sufficiently different to be classified as separate species.

A tangle of tangle ferns – the new species growing intermixed with Gleichenia dicarpa, western South Island. Photo Leon Perrie, Te Papa.

You might, then, appreciate my surprise and excitement at finding an obviously different species while inspecting Te Papa’s specimens of Gleichenia.  The differences were so great, I thought I was hallucinating.  I was using a microscope at the time, but the differences are evident to the naked eye once you know what to look for.

I’ve now checked through New Zealand’s three biggest botanical collections – Landcare Research, Auckland Museum, and Te Papa.  Between them they hold several hundred Gleichenia specimens, but just 13 of the new species (only 2 of Te Papa’s 250 specimens of Gleichenia are the new species).

Using these collections I’ve been able to determine:
• how to distinguish the new species from the other species of Gleichenia in New Zealand (and Australia).
• where it occurs – it appears restricted to just three regions of New Zealand.
• how common it is – apparently not very.

This is a clear demonstration of the value of such collections – they document our biodiversity.  I knew a lot about this new species without even stepping outside.

A paper establishing a scientific name for the new species will be published soon.  I’ll then post on how to distinguish the new species.

Why has this new species not been detected before?  There’s no doubt that tangle ferns are a difficult group, and they’ve probably been neglected.  There is still much to learn about the boundaries between the presently recognised species in New Zealand - Gleichenia alpina, G. dicarpa, and G. microphylla - and I’m working on that too.

Images associated with some of Te Papa’s Gleichenia specimens.

Ferns of New Caledonia that are very different to those in New Zealand

You’ll never have seen anything like these New Caledonia ferns in New Zealand, unless you’ve been to a very interesting garden (which I’d love an invitation to!). These are photos from my recent fern collecting trip.

Dipteris conjugata. This is a very distinctive species with its un-fern like, c. 1 metre wide fronds. It is can be common on sunny, roadside banks. The same species occurs in south-east Asia to Australia and Fiji. The closest relatives in New Zealand – and it is a distant relationship – are Gleichenia, Sticherus, and Dicranopteris. Photo Leon Perrie. © Te Papa.

Dipteris conjugata. The spore-producing structures (sporangia) occur in clusters (sori) spread over the underside of the frond. Photo Leon Perrie. © Te Papa.

Austrogramme marginata. You can be forgiven for thinking this is an Asplenium birds-nest fern. But the resemblance is only superficial, and it is actually in the Pteridaceae family! The closest relative in New Zealand is probably Anogramma (and/or Pteris). Photo Leon Perrie. © Te Papa.

Drynaria rigidula. A so-called basket fern. These are epiphytic ferns that have some of their fronds modified (centre of the photograph) to catch litter and organic debris, which on decomposing provides nutrients to the plant. Widespread through south-east Asia and the tropical Pacific. The closest relatives in New Zealand are Pyrrosia and Microsorum. Photo Leon Perrie. © Te Papa.

Prosaptia contigua. Looks a bit like New Zealand’s Ctenopteris heterophylla except the reproductive structures are clustered into cups at the apices of the frond segments. Widespread through south-east Asia and the tropical Pacific. The closest relatives in New Zealand are Ctenopteris and Grammitis. Photo Leon Perrie. © Te Papa.

Stromatopteris moniliformis. A fascinating fern for anyone interested in fern evolution. This is the only species in the genus Stromatopteris, and its relationships were intensely debated. Now classified in the Gleicheniaceae, along with the following genera found in New Zealand: Dicranopteris, Gleichenia, and Sticherus. I saw Stromatopteris only in the maquis vegetation, where it was one of very few ferns present. At the base of the image on the left is a young Dracophyllum. Photo Leon Perrie. © Te Papa.

Selaginella hordeiformis (?). A lycophyte rather than a fern. No Selaginella are native to New Zealand, but misfortunate conservationists and gardeners may be familiar with the introduced Selaginella kraussiana. Despite the latter’s diminutive stature, it carpets the floor of wet forests (and gardens), choking regeneration. New Caledonia is home to several Selaginella species that produce erect ‘fronds’, although none as big as Fiji’s Selaginella viridangula which can be over 1.5 m tall! Photo Leon Perrie. © Te Papa.

Tectaria sinuata. New Zealand is seemingly too cold for this large group of ferns. The closest relative in New Zealand, is believe it or not, the epiphytic Arthropteris. Photo Leon Perrie. © Te Papa.

New Caledonian ferns with close relatives in New Zealand

A lot of New Caledonian species belong to fern genera that also occur in New Zealand. Some look very similar to New Zealand species, whereas others are quite different!  Here’s a few from my recent trip.

Cyathea albifrons. Like New Zealand’s silver fern (Cyathea dealbata), the fronds are white underneath. But the two species are not closely related. Cyathea albifrons was the dominant tree fern in the forested serpentine areas that we visited. Photo Leon Perrie. © Te Papa.

Cyathea intermedia. I’ve seen competing claims about whether New Zealand’s Cyathea medullaris or New Caledonia’s Cyathea intermedia was the world’s tallest tree fern. Having now seen them both, my vote is with Cyathea intermedia; easily. Majestically massive. Photo Leon Perrie. © Te Papa.

Dicksonia thyrsopteroides. Superficially similar to New Zealand’s Dicksonia squarrosa (wheki), but it is less hairy and the different-looking fertile parts of the frond are distinctive (see below). Photo Leon Perrie. © Te Papa.

Dicksonia thyrsopteroides. The fertile parts of the frond, right and centre, look very different to the sterile parts, to the far left. Photo Leon Perrie. © Te Papa.

Trichomanes laetum. What a cute little fuzz ball! According to my books, laetum is Latin for attractive or joyful. The closest relative in New Zealand is Trichomanes elongatum. Photo Leon Perrie. © Te Papa.

Hymenophyllum rolandi-principis. There are lots of Hymenophyllum species in New Zealand, but I think none so elegant as this. Grows as an epiphyte in high altitude forest. Photo Leon Perrie. © Te Papa.

Adiantum novae-caledoniae. I suspect our DNA analyses will confirm this as being very closely related to Adiantum cunninghamii, A. fulvum, and A. viridescens of New Zealand, and Adiantum silvaticum of Australia. Photo Leon Perrie. © Te Papa.

Asplenium oligolepidum. An uncommon epiphyte. Preliminary DNA analyses have suggested that its relationship to New Zealand’s Asplenium oblongifolium and Asplenium obtusatum is not as close as one might suspect from its looks. Photo Leon Perrie. © Te Papa.

Blechnum obtusatum. Common around streams. A very handsome fern that could make a wonderful garden plant. Recalls somewhat Blechnum fluviatile or Blechnum durum, but unpublished DNA analyses indicate the closest New Zealand relatives are probably those currently classified as Doodia. Photo Leon Perrie. © Te Papa.

Blechnum corbassonii. A fairly common forest fern. Part of a group of New Caledonian Blechnum ferns that I found difficult to work with, but which are apparently related to Blechnum novae-zelandiae. Photo Leon Perrie. © Te Papa.

Blechnum diversifolium. Unusual for a Blechnum in that the frond is twice-divided. Blechnum fraseri in New Zealand does the same, and perhaps they’re related. Photo Leon Perrie. © Te Papa.

Sticherus montaguei. Reasonably common at the margins of upland forests. Up close it looks like Sticherus flabellatus, but it is much, much bigger. Photo Leon Perrie. © Te Papa.

New Caledonian ferns shared with New Zealand

About 35 species of fern are found in both New Caledonia and New Zealand. That’s about 13% and 18% of the total species in each area.  Almost all of these are widespread species that are also found elsewhere in the Pacific (and beyond).

Here’s a few of them that I saw during my recent field work in New Caledonia:

Dicranopteris linearis is one of the world’s most widespread ferns. In New Zealand it is only found at geothermal sites in the central North Island, but it is widespread through the Pacific. In New Caledonia it is abundant where the vegetation is recovering from disturbance, such as in the Melaleuca savannah. From the morphological diversity present in New Caledonia, I suspect more than one species is present. Dicranopteris is distinguished from the related Gleichenia and Sticherus by the naked stems below the frond-forks. Photo Leon Perrie. © Te Papa.

Lycopodiella cernua is a lycophyte rather than a fern. It is often found with Dicranopteris linearis, at sites where the vegetation has been disturbed.  It gets much bigger in New Caledonia than in New Zealand. Photo Leon Perrie. © Te Papa.

Schizaea dichotoma, fan fern. This is just a young, unfurling frond. The red colour doesn’t last. Photo Leon Perrie. © Te Papa.

Tmesipteris sigmatifolia, fork fern. Grows on tree fern trunks. Seemed common in New Caledonia. Largely restricted to kauri forest in New Zealand, although other species are widespread. Photo Leon Perrie. © Te Papa.

Histiopteris incisa, water fern. A relative of bracken (Pteridium esculentum), but generally found at wetter sites. New Caledonian plants have a ‘tougher’ look compared to those in New Zealand. Photo Leon Perrie. (c) Te Papa.

Gleichenia dicarpa, tangle fern. Up close, New Caledonian plants look very different to those from New Zealand. We were already working on a taxonomic revision of this species. Photo Leon Perrie. © Te Papa.

Going (Lady) Gaga over ferns

USA fern taxonomists have created a minor stir after re-classifying a group of central American ferns into a new genus named Gaga, after the singer Lady Gaga.

Abstract of the article formally naming the new genus Gaga.

Youtube video of the taxonomists discussing their research.

The researchers say the naming for Lady Gaga was in honour of “her articulate and fervent defence of equality and individual expression in today’s society”, linking the celebration of diversity within humans to the study of the intricate diversity in this group of ferns. Further, the Gaga ferns contain a stretch of DNA with the nucleotides GAGA that distinguish them from their close relatives. Lady Gaga also once wore a costume resembling a fern gametophyte (presumably not knowingly), and these taxonomists are apparently big fans of her music.

The rock fern, Cheilanthes sieberi, a New Zealand relative of the newly re-named Gaga ferns. Photo Leon Perrie. © Te Papa.

The 19 species of Gaga ferns were previously classified in the genus Cheilanthes. However, DNA analyses of evolutionary relationships have shown that Cheilanthes is composed of a multitude of unrelated groups, which are therefore undergoing extensive re-classification; Gaga is but one example. From our own research and that of others, it appears that the Cheilanthes in New Zealand are true Cheilanthes and won’t be re-classified.

Abstract of our paper examining the generic classification of New Zealand Pteridaceae, including Cheilanthes.

Naming new species or genera after people is not the ‘done thing’ amongst (most) New Zealand plant taxonomists. The following words I read as a student still resonate strongly with me:

[taxonomists should] “base new names on character states or distinctive habitats that assist in distinguishing a new taxon from its near relatives” (Webb & Edgar 1999).

Utility over sycophancy, perhaps?

That said, sometimes it is hard to come up with a new, unique name, particularly in groups of organisms that contain a lot of undescribed species. Te Papa’s snail expert, Bruce Marshall, has 5 genera and more than 20 species named after him.

What if we were to extend the taxonomic honouring of celebrity to New ZealandDobbynii or Finnii, or Irenei or Danii anyone?

New Caledonia fern collecting

I’m just back from three weeks collecting ferns in New Caledonia.

For a place so close to New Zealand (shorter flight time than to Australia), I knew very little about New Caledonia. I expect that is true for many New Zealanders, and it presumably reflects our very different cultures, not least being the language difference (French predominates in New Caledonia, and English* in New Zealand).

New Caledonia is not an independent country but a special collectivity of France. Nouméa, its largest city, is like a piece of France transplanted to the tropical Pacific. The original Melanesian character is perhaps most strongly retained in the (north-)east.

Wikipedia page on New Caledonia.

Wikipedia page on the indigenous Kanak people.

Some of Te Papa’s existing collections from New Caledonia.

We stayed in villages during some of our trip. Here at Bas Coulna, before we left to climb Mount Panié, we had a traditional-type hut. Photo Leon Perrie. © Te Papa.

Funded principally by a grant from the USA’s National Science Foundation, our collecting expedition was led by Matt von Konrat (Field Museum), Blanka Shaw (Duke University), and Louis Thouvenot, who was our guide and translator (none of the others in the expedition had been to New Caledonia before or spoke French, although Juan’s Spanish was useful on many occasions). The main goal was to collect Frullania liverworts, but we variously collected mosses, liverworts, and lichens – these are all small plants that are often neglected. I was invited along to collect ferns.

Interview with Radio Australia’s Pacific Beat programme about the expedition.

Blog post on similar expedition to Fiji in 2011.

The black stems, each only about 1 mm wide, of a Frullania liverwort creeping over a white lichen on the trunk of a mangrove tree. Photo Leon Perrie. © Te Papa.

New Caledonia is home to about 270 ferns and lycophytes. That’s more than New Zealand, despite a land area less than 10%. About 35% of New Caledonia’s ferns and lycophytes are endemic (i.e., only found there), which is very high for a tropical Pacific island. However, the last comprehensive account is from 1969, and it is clear that much revision is needed. A reflection of this is that there are (at least) two species of new tree fern needing scientific description. During the three week expedition, I made 232 collections, of at least 160 different species. These include new species, new records for New Caledonia, and rediscoveries (species not recorded for a long time).

Te Papa’s updated checklist of Fiji’s ferns, which I hope to replicate for New Caledonia.

The Endemia website includes photos of many of New Caledonia’s ferns, and is an excellent photographic resource about New Caledonia’s biodiversity

In coming days I’ll post about some of the plants I saw, particularly, of course, the ferns.

Trip leader Matt von Konrat collecting Frullania liverworts up a mangrove. Photo Leon Perrie. © Te Papa.

Collecting near Tinou. Photo Leon Perrie. © Te Papa.

All available space in our lodgings was often given over to drying specimens. Louis’s bed is somewhere under these paper packets. Photo Leon Perrie. © Te Papa.

On our way to Mount Panié. We were fortunate to have horses carry our packs for the first part of the trek. Photo Leon Perrie. © Te Papa.

Maurice, one of our guides for Mount Panié, using a wreath of the fern Paesia rugosula to complement the shade of his cap. Photo Leon Perrie. © Te Papa.

Albeit clearly exhausted, here’s proof that I did make it to the summit of Mount Panié, New Caledonia’s highest point at 1629 m above sea level. Photo Leon Perrie. © Te Papa.

The expedition couldn’t have been the success it was without the assistance of many, especially Louis Thouvenot, as well as the Nouméa herbarium, the government land managers, the Kanak land owners and guides, and our contacts at Dayu Biik, Conservation International, and Société Calédonienne d’Ornithologie.

* I can note that the so-called ‘English’ speech of the two (monolingual) New Zealanders was constantly belittled by the other members (all multilingual) of the expedition, none of whom spoke English as a first language. Matt and I weren’t sure what to make of this.

Curiosities, world-firsts, and monsters – fern spotting in Wellington

On Saturday I joined the Wellington Botanical Society’s field trip to Wright Hill in Karori, Wellington. Wellington city would not be my first choice of locality for fern spotting, but we still found plenty to keep me interested.

The striking filmy fern Hymenophyllum flexuosum. The scientific name means wavy or undulating (flexuose) membranous (hymen) leaf (phyllum). The fronds of most filmy ferns are only one cell thick! Hymenophyllum flexuosum usually grows on rocks, but can be a low epiphyte on trees. Photo © Leon Perrie.

The filmy ferns Hymenophyllum flexuosum and Trichomanes endlicherianum are always pleasing finds. Although widespread, they are not common (but not so rare to be on the national Threatened or At Risk lists). We found them together on a shaded rock face. Rock outcrops are always worth a close inspection because they can be home to species not found in other nearby habitats.

Trichomanes endlicherianum. Note the tubular reproductive structures that characterise the genus. By contrast, the reproductive structures in Hymenophyllum are each enclosed by two distinct flaps. Trichomanes endlicherianum is almost always found on shaded, near-vertical rock faces. It occasionally grows on trees, particularly at the bases of nikau palms. The similar Trichomanes venosum commonly grows on the trunks of tree ferns, but is easily distinguished on account of having multiple veins in each segment of the frond. Photo © Leon Perrie.

The shield fern Polystichum silvaticum was also an interesting find. I spotted this less than half an hour after I had predicted we wouldn’t find it because I thought the environment was not wet or cold enough (and I had forgotten that I had previously collected it from nearby Makara about six years ago). Its presence says something about Karori’s climate.

The shield-less shield fern Polystichum silvaticum. Photo © Leon Perrie.

The reproductive structures of Polystichum silvaticum are naked, lacking the shield-like protective coverings that characterise its relatives. Photo © Leon Perrie.

But my day’s highlight was finding a hybrid between Polystichum neozelandicum and P. silvaticum, which is the first time this has ever been recorded. Some Polystichum hybrid combinations are quite common, particularly, P. neozelandicum × P. vestitum. However, P. neozelandicum and P. silvaticum rarely grow in close proximity, limiting the likelihood of their hybridisation.

First record of the hybrid between Polystichum neozelandicum and P. silvaticum. Photo © Leon Perrie.

We also spotted a monstrous form of hound’s tongue fern, Microsorum pustulatum. These are due to damage to the growing bud, such that it produces fronds that divide more than is typical. During the nineteenth-century ‘fern craze’, such abnormalities were highly prized (and financially-valued) by collectors. Hound’s tongue fern seems particularly predisposed to monstrosities: in the last year I have seen similar plants near Eastbourne and in the Waioeka Gorge, but only at low frequencies (c. 1%).

A so-called monstrous or crested frond of hound’s tongue fern, Microsorum pustulatum. The lobes of the fronds of hound’s tongue fern do not normally fork at their apices. Photo © Leon Perrie.

Learn more about hound’s tongue fern on the Common New Zealand Ferns webpages.

Te Radar’s vegetable with charisma

Which vegetables do you think have charisma? 

In Tuesday night’s television programme Radar Across The Pacific, comedian Te Radar was given “fiddle fern” to eat.  He seemed to be impressed by it, describing it as having charisma.

TV One’s Radar Across The Pacific.

Te Radar was eating the young, unfurling fronds of a fern.  These still-coiled fronds are variously called croziers or fiddleheads or, in New Zealand, koru.  Fern fiddleheads are a common vegetable in some parts of the world.

Ota dina, Diplazium dietrichianum (or D. esculentum), Fiji. Photo Leon Perrie. © Te Papa.

I couldn’t tell for sure but there’s a good chance that the fern Te Radar was eating was Diplazium dietrichianum, ota dina (or Diplazium esculentum).  The similar Diplazium ecsculentum is commonly eaten in Asia.  The second part of its scientific name, “esculentum“, means edible.  The related Diplazium proliferum, ota lalabe, is also eaten in Fiji and elsewhere.

During our 2011 field work in Fiji, we saw Diplazium fiddleheads being harvested for sale at the Suva market.

Blog post about our 2011 fern collecting in Fiji.

Ota lalabe, Diplazium proliferum, Fiji. Photo Leon Perrie. © Te Papa.

A New Zealand equivalent comes from the hen & chickens fern (manamana or mouku, Asplenium bulbiferum).  Its fiddleheads are known as pikopiko.  The popularity of pikopiko as a vegetable seems to be reviving, and it is commercially available.

Pikopiko, or the young, uncurling frond (koru) of hen & chickens fern (Asplenium bulbiferum, manamana, mouku), Wellington, New Zealand. Photo Leon Perrie. © Te Papa.

More on hen and chickens ferns from Te Papa’s Collections Online.

West Coast Fern Fieldwork 2012, 6 – animal miscellany

Here are a few, token animal photos to finish this account of our fieldwork.

South Island fernbird, Bowdleria punctata punctata, in manuka bordering tangle fern (Gleichenia)-dominated pakihi near Westport. This was the first fernbird I have ever seen/noticed, but we saw/heard several others elsewhere during our trip. Unfortunately my camera is optimised for close-ups (since plants don’t run away), and has a terrible zoom – hence this blurry picture. Photo Leon Perrie. © Te Papa.

A western weka, Gallirallus australis australis, making a mess of DOC’s lawn. Enchanting birds, but somewhat of a road hazard, and evidently careless gardeners. Tauranga Bay, Cape Foulwind, near Westport. Photo Leon Perrie. © Te Papa.

c. 10 cm long slug, Stockton. I nearly stepped on it during my excitement of finding a couple of uncommon ferns. The slug’s impressive size was enough to distract me from the ferns, momentarily. Photo Leon Perrie. © Te Papa.

Mammals impersonating slugs – seals at Tauranga Bay, Cape Foulwind, near Westport. Photo Leon Perrie. © Te Papa.

South Island robins, Petroica australis australis, are regular companions during forest walks in many parts of the South Island. Photo Leon Perrie. © Te Papa.

Other blog posts about our West Coast fern fieldwork cover:

What we were doing.

Where we went.

Sticherus (umbrella ferns).

New, problematic, and interesting species.

Favourite photos.

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