Journal Number 93
November 2005


NOTES etc


Pollination ecology of four epiphytic orchids of New Zealand
, by Carlos A Lehnebach
and Alastair W Robertson recently appeared in Annals of Botany 2004; 93: 773-781 www.aob.oupjournals.org.

The abstract is reprinted below...

  • Background and aims: In New Zealand epiphytic orchids are represented by four genera and eight species. The genera Earina (three species) and Winika (one species) are the most conspicuous and widespread. These are likely to be some of the southernmost distributed genera of epiphytic orchids in the world.
  • Methods: To identify the pollination strategies that have evolved in these orchids, hand-pollination treatments were done and floral visitors were observed in several wild populations at two areas of southern North Island (approx. 40°S). Pollen : ovule ratio and osmophores were also studied and the total carbohydrate content of the nectar produced by each species was measured.
  • Key results: Earina autumnalis and Earina mucronata are self-compatible, whereas Earina aestivalis and Winika cunninghamii appear to be partially self-incompatible. All four orchids are incapable of autonomous self pollinating and therefore completely dependent on pollinators to set fruits. Floral visitors observed in the genus Earina belong to Diptera, Coleoptera and Hymenoptera and to Diptera and Hymenoptera in W. cunninghamii.
  • Conclusions: Contrary to many epiphytic orchids in the tropics, the orchid/pollinator relationship in these orchids is unspecialised and flowers are visited by a wide range of insects. Putative pollinators are flies of the families Bibionidae, Calliphoridae, Syrphidae and Tachinidae. All four orchids display anthecological adaptations to a myophilous pollination system such as simple flowers, well-exposed reproductive structures, easily accessed nectar and high pollen : ovule ratios.


This paper demonstrates another unique quality of NZ orchids' adaptation to an insect poor environment.
Not only are they the greatest self-pollinators in the world, but when they are insect pollinated they are not fussy.
No exclusive orchid/insect co-evolution pollination syndrome here - Ed.




Brian Tyler writes that Nematoceras iridescens emerges from the ground as the ice-cream
cone that appears typical of other members of the N. rivularis group. His photographs prove it:


Nematoceras iridescens




John Neufeld wrote (1 August), "I am a member of an organization in Manitoba Canada that appears to be similar to your own. We are called Native Orchid Conservation Inc.
Our web site is www.nativeorchid.com.

I will be visiting your fine country this year for about 3 weeks starting at the beginning of December.
I would love to see some of your native orchids when I visit. Is there any information you can give to me about the native orchids of New Zealand, and where they might be found. I would be happy to reciprocate if anyone is interested in the orchids of Manitoba.... Here our peak orchid season is drawing to a glorious close.

We have had a very strange summer in our Province. It started off as the wettest and coldest summer ever. The orchids though late, have bloomed magnificently. Ten members of our group, including my wife Chris and I, recently completed a trip to the north part of our Province near Churchill Manitoba. This is just below the Arctic circle. You may have heard of it, as they advertise themselves as the polar bear capital of the world. In Manitoba we expect to host a group of international native orchid lovers that have an annual conference.

Their name is Native Orchid Conference and we expect them to have their annual meeting in our province next July. Perhaps some ambitious New Zealanders would like to attend? We could show you a wonderful time! And you could meet other lovers of native orchids from around North America and even Europe. I have never been to one of their conferences yet. This year they meet in North Carolina in a week or two ....

I hope John can join us at Iwitahi - Ed.




Pohutukawa Post, summer 2003, carried a piece by Scott Kusabs, ARC Park Ranger, Hunua Regional Park:

Have we found the missing link? A recent expedition in the Hunua Regional Park involving Southern Sector Park Rangers and local orchid enthusiasts Eric Scanlen and Phil Mitchell have located populations of the orchid species Nematoceras triloba. Although this is not a rare species, there are two different varieties or taxa Nematoceras "Rimutaka" [J82:16] and N. "Tricepts" [J76:40] within the species.

These populations are alongside the very popular Wairoa Loop track and can easily be overlooked by the untrained eye. Three specimens of both taxa were collected to be sent off to orchid expert Brian Molloy in Christchurch for studying to ascertain whether the two taxa are different species. DNA sampling in Canberra will be used to help with this diagnosis. If indeed they are different species they will need to be renamed and described.

We are not sure what (or who) the expression "missing link" refers to - Ed.




Situated in the province of West Java in the south of Jakarta, Indonesia, Cibodas Biosphere
Reserve is an example of an ecosystem in the humid tropics undergoing strong human pressure.
The Gunung Gede Pangrango National Park constitutes the core area of the biosphere reserve.
It includes twinned volcanoes and mountainous rain forests with many Javan endemic species.

The impact of various human activities on the core area is growing due to tourism development and increasing population density in the surrounding areas. Shortage of fuelwood and income force local people to collect wood and nontimber forest products in the core area.

Major habitats & land cover types: lowland rainforest; montane/sub-montane rainforest characterized by Podocarpus spp., laurels (Litsea spp.), oaks (Lithocarpus spp. and Quercus spp.), chestnut (Castanopsis spp.) and Schima wallachi; sub-alpine or elfin forest with Ranunculus spp., Viola spp., Vaccinium spp. etc; grass plains dominated by Javan edelweiss (Anaphalis javanica) and with gentian (Gentiana quadrifaria), terrestrial orchid (Thelymitra javanica) and bramble (Rubus lineatus). E-mail tngp@cianjur.wasantara.net.id.




The Magazine of the Queen Elizabeth II National Trust, Issue 59, December 2003, reported on a new kowhai species: "Sophora molloyi is `as tough as old boots' and like its namesake Brian Molloy, hardy in all extremes of weather.

In 2001 Dr Peter Heenan of Landcare Research and Peter de Lange of the Department of Conservation named five new species of kowhai, including the one named after Brian Molloy. Sophora molloyi has evolved to grow on harsh and inhospitable sites on dry, exposed headlands around Cook Strait, Kapiti Island, and parts of the lower North Island."




Gordon Sylvester found Pterostylis trullifolia and Acianthus sinclairii at Rarangi just out of
Blenheim ER.39 - 14 Jul 04 in flower.




Mycorrhiza: Grant, CD; Koch, J. 2003. Orchid species succession in rehabilitated bauxite mines in Western Australia. Australian Journal of Botany. 51(4):453-457.

Twenty-three orchid species were recorded in Alcoa's permanent vegetation-monitoring plots in unmined and rehabilitated jarrah forest. Of these, 22 were identified in the unmined jarrah forest and 20 were recorded in rehabilitated areas of between 1 and 31 years old.

Three species (Cyrtostylis ovata, Lyperanthus serratus and Prasophyllum elatum) were only recorded in the unmined forest and one species was only recorded in rehabilitated areas (Diuris cartnata).

The overall density of native orchids in the forest was 13,755 plants/ha, 10 times greater than the density in rehabilitated areas (1381 plants/ha).

The most abundant species in the forest were Cyrtostylis robusta, Caladenia flava, Pterostylis nana and Thelymitra crinita, all with densities greater than 1000 plants/ha. The most abundant species in the rehabilitated areas were Microtis media, Disa bracteata (an introduced species), Caladenia flava, Pterostylis nana, Diuris longifolia and Pterostylis vittata, all with densities greater than 60 plants/ha.

In rehabilitation older than 10 years, the density of orchids increased to 2685 plants/ha. Burning in rehabilitated areas resulted in large increases in orchid densities. It is believed that orchid colonisation of rehabilitated bauxite mines is dependent on symbiotic mycorrhiza, which are in turn dependent on development of an organic litter component in the soil.




Snug GreenhoodRare orchid zone blasted, reported Danny Rose in the Hobart Mercury on 8 September 2004,"The Snug Greenhood orchid, which is listed as an endangered species and found only in Tasmania, is known to grow in the Blowhole Valley of the Southwest Wilderness World Heritage Area.

State Government spokesman Craig Martin confirmed yesterday the orchids were growing in the area where 13 holes were blasted recently to create water catchments." Pterostylis atriola DL Jones 1998 is listed as endangered.

This followed an allegation by Greens leader Peg Putt. "The Snug Greenhood is only found in Tasmania, in six small sites," Ms Putt said. "One of which is in the Blowhole Valley and they could have blown it up."

Snug Greenhood is endemic to Tasmania and is confined to six small sites on Snug Plains, where it occupies less than 10 hectares. The total number in existence has been estimated at 100. The Blowhole Valley population was first seen in 1992 and has not been seen again despite searches nearly every year since.

Mr Martin said the explosions would not hurt the orchids, and the subsequent controlled burnoffs would actually help it to regenerate. Indeed Tasmanian orchidologists Hans and Annie Wapstra have written that most plants grow on the edge of forestry tracks, though they are absent from adjacent suitable habitat suggesting that the Snug Greenhood favours a high degree of disturbance to proliferate."

Genuine concern or political headline grabbing? All is not always as it seems.

 



In July a 70 year old Peruvian orchid grower was sentenced to 21 months in prison for smuggling internationally protected wild orchids into the United States, hidden among legal nursery-raised plants. Manuel Arias Silva pleaded guilty to one count each of smuggling, conspiracy and filing false customs statements.

He admitted shipping 2,050 orchids, including an endangered species of Phragmipedium or tropical lady slipper orchid, worth $45,500. Arias had been one of only three Peruvian growers with permission to cultivate endangered and newly discovered orchids.

Nursery-raised varieties can be exported from Peru with government permits, but he was accused of shipping wild plants, which are considered seriously endangered in the wild and are protected by international treaty. The plants were shipped from 1999-2003 to dealer George Norris of Houston. Norris also pleaded guilty. The investigation was based on a tip that Norris was selling endangered species on the Internet.





Orthoceras is a prehistoric cephalopod related to the modern day squid, cuttlefish, and octopus.
It dates back to ~350 million years ago. Fossils are found in the Sahara Desert, Morocco.

Microtis is a mollusc which produces the common "thumbnail" shell. It is also a genus of hamster-like rodents.

The botanical and zoological nomenclatures are separate - Ed.




A correspondent to Orchid Digest wrote, "...one should be very careful identifying orchids from pictures, especially so when these are lacking in pertinent details.... Plants vary, not only at a regional level but also at population level.

The genus Dactylorhiza belongs to a taxonomist's worst nightmare. For various reasons there is still a lot of confusion about the exact species boundaries within this genus (the species count hence varies from ~22 to ~80, depending on whom you ask), and added to this comes the fact that several species easily hybridise in several directions, resulting in local hybrid swarms which phenotypically vary according to the location.

It appears that especially in Northwestern Europe and the Alps this genus is going through a stage of active evolution and adaptive radiation, which may well be in response to rapidly changing environmental conditions. Not only do populations show a strong tendency to form local ecotypes (which in some cases, with only some 20-30 km in between them, may look like they're entirely different species), it has also been shown that stable species have arisen as a result of hybridisation (and in some cases hybridisation followed by subsequent chromosome doubling) or by autotetraploidisation.

In several cases these 'derived' species and forms inhabit narrowly delimited habitats from which other members of the genus are absent. Dactylorhiza sphagnicola for instance, which inhabits ultra-acid raised sphagnum bogs in northwestern Europe in which no other dactylorhizas occur, is proven to be a tetraploid hybrid of Dactylorhiza fuchsii and D. incarnata, while the Eurosiberian D. maculata seems to be a stabilised autotetraploid of D. fuchsii.

It is because of all this that I often think it funny when yet another tropical species has been described because of a slightly different staminode or oddly twisted sepals or whatever. Plant species vary, as do we, and therefore one has to be careful when assigning names, especially so when all that is at hand is a picture."

There is a lot we can learn by reading about the orchids of other countries.
1. Bruce Irwin's drawings in this issue of a small Nematoceras hypogaea show how carefully even that plant
    must be positioned if one is to assess the shape of the dorsal sepal from a picture.
2. I am sure N. triloba forms local ecotypes.
3. We know several Thelymitra are stable hybrids.
4. I still wonder if autotetraploidy explains the huge double flowered Singularybas oblongus I jokingly
   dubbed "C. quadriplex ".
5. I would bet that Pterostylis "hybridises in several directions resulting in local hybrid swarms "- Ed.




September 18 found Tony Silbery, Pat Enright and me, looking for Nematoceras longipetalus in Lowes Bush, now a DOC reserve, near Masterton. It's the orchid I drew for the cover of J83: longer than wide leaf, tiny apiculus, plain green; long pointed tip to dorsal sepal (Fig 13). It was in full flower again this time.

I was down, wet-kneed, taking photographs when Pat called out that he found a N. aff. trilobus in full flower a couple of metres away; it was N. hypogaea (Fig 14,): kidney shaped leaves, wider than long, heavily marked with brown, with a big apiculus; rounded dorsal sepal, frayed labellar edge. "Gosh," he remarked cynically, "next thing we'll find hybrids."

Then, "Hello, here's something different." Indeed it was-a colony, geographically between, and structurally between, the two species: 50 or so plants thriving with hybrid vigour; very similar to Bruce Irwin's drawing of the N. iridescens x N. aff. triloba (?) hybrid in this issue (page 26).

The Masterton plants are shown in (Fig 15): short pointed dorsal sepal, leaves round with a big apiculus, marked with brown.

Pat Enright described the habitat: "N. longipetala grows in reasonablelight usually around pools of ponded water that would probably dry out somewhat in summer. N. hypogaea grows in less wet conditions on the forest floor as does the putative hybrid which is actually growing on a tree root.

The main tree species is poe kahikatea with scattered swamp maire and pukatea red young Coprosma robusta (1m high) and young hangehange with the tree fern Dicksonia squarrosa common. Pneumatoptenis pennigera is also common in the area. The area is near the edge of the bush reserve hence has fairly good light."

Nematoceras longipetalusN. hypogaeaN iridescens x N. aff triloba

Nematoceras

 

 

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