Tag Archives: native

Delight and Disaster in the Rubbish Heap

I’m always keen to add to the number of plants I can recognise. Weeds are a profitable group in that respect.

One of the species of poroporo, Solanum aviculare. Photo © Leon Perrie.

Recently my wife pointed out an interesting looking organic rubbish heap on the grounds of Massey University that was home to an odd-looking Solanum. Imagine my delight when, on closer inspection, I found it to be not a weedy exotic but a real indigenous treasure: Solanum aviculare.

Solanum aviculare is one of two similar species known as poroporo. The other is Solanum laciniatum, which is very common and widespread through New Zealand. Solanum aviculare, on the other hand, is on the Threatened Plants lists as “At Risk/Declining”. I have never knowingly seen it before, so I was very excited!

Handily, at this rubbish heap the two species of poroporo were growing together, facilitating easy comparison. Although their leaves were strikingly different here, the best way to distinguish them is by their flowers: the petals of S. aviculare are less fused and more deeply cut than those of S. laciniatum.

The two poroporo side-by-side. Solanum laciniatum is on the left, Solanum aviculare on the right. Photo © Leon Perrie.

Flowers of the two poroporo. Solanum laciniatum is on the left, Solanum aviculare on the right. Photos © Leon Perrie.

The DISASTER comes because a week after taking these pictures, this rubbish heap was “cleaned up” – an unfortunate demise for this rarity! Hopefully we can find more S. aviculare locally.

Unripe fruit of poroporo, Solanum laciniatum. Photo © Leon Perrie.

Both poroporo species have similar fruit, which can be eaten when they are ripe (when orange, with bursting skin). However, they’re poisonous when green and unripe, so be wary! They belong to the same genus as tomatoes, potatoes, and black nightshade, and the same family as deadly nightshade. It’s a minefield of nutrition and toxicity.

Interestingly, both Solanum aviculare and S. laciniatum occur in Australia, where they are known as kangaroo apple.

Native plants for your garden

Titoki, Alectryon excelsus.

Do you live in the Wellington region, want to have native plants in your garden, but don’t know what to choose?

Then the Greater Wellington Regional Council has produced just what you need: the Wellington Regional Native Plant Guide.  I attended the recent launch of the revised 2010 edition.

Wellington Regional Native Plant Guide.

Lists are provided of native plants ideal for 14 different sub-regions, from the southern coasts to the Kapiti dunelands to the northern Wairarapa.

As the guide says:

PLANTS ARE GREAT,

NATIVES ARE BETTER,

ECO-SOURCED IS THE BEST

Weedy ferns

Chris Horne of the Wellington Botanical Society recently sent me a fern frond they collected on one of their trips. Although the frond is small and lacking the diagnostic reproductive characters, I think it is the introduced holly fern (Cyrtomium falcatum). It looks like the shining spleenwort (Asplenium oblongifolium), but the flanges, or ‘teeth’, of the frond segments are distinctive (amongst ferns in New Zealand).

Holly fern, Cyrtomium falcatum, in cultivation.

Holly fern, Cyrtomium falcatum, in cultivation.

Holly fern and shining spleenwort can be readily distinguished when mature. The reproductive structures of the holly fern resemble those of the shield ferns (Polystichum), to which it is related, while the shining spleenwort has typical spleenwort reproductive structures.

The sori, or reproductive structures, on the underside of fronds of holly fern, Cyrtomium falcatum, on the left and shining spleenwort, Asplenium oblongifolium, on the right.

The sori, or reproductive structures, on the underside of fronds of holly fern, Cyrtomium falcatum, on the left and shining spleenwort, Asplenium oblongifolium, on the right.

Holly fern is native to Asia, but it is sporadically cultivated in New Zealand, and it has become weedy in several parts of the country. Steve Benham wrote an article for the Auckland Botanical Society Journal (v.63 (1), pp.25-27) suggesting gardeners should be dissuaded from cultivating holly fern in the Northland and Auckland regions, because of its invasiveness in that part of the country.

It is certainly a fern that should be monitored, so it would be good to get reports of holly fern growing wild.

Two other weedy ferns to keep an eye out for are common polypody, Polypodium vulgare, and the male fern, Dryopteris filix-mas.

The common polypody, from Europe and Asia, is a common weed on Banks Peninsula, and it has recently been found in Wellington (near Plimmerton) and Marlborough (near Kaikoura and near Hanmer Springs).

It looks like the native hound’s tongue, Microsorum pustulatum, but can be distinguished by its frond being dissected right to the stem of the frond. Polypodium vulgare can be a terrible, smothering weed, so it is important that it is stopped from spreading further. Regional Councils should be notified of any additional localities.

caption

Fronds of common polypody, Polypodium vulgare, on the left and hound's tongue, Microsorum pustulatum, on the right. The blue arrows indicate the difference in frond dissection.

The male fern, Dryopteris filix-mas, is also from Europe, and has established in many parts of New Zealand. I have been amazed at how widespread it is in the South Island, but I haven’t collected it as often as I should have, and Te Papa’s collections don’t do its invasiveness justice. Male fern is unusual in that it can invade relatively intact native forest, making it a formidable weed.  A very similar species, Dryopteris affinis, is also weedy in New Zealand.

Male fern

Male fern, Dryopteris filix-mas.

Distribution of male fern, Dryopteris filix-mas, in New Zealand, based on specimens in Te Papa's WELT herbarium. Note that this is a significant under-representation.

Distribution of male fern, Dryopteris filix-mas, in New Zealand, based on specimens in Te Papa's WELT herbarium. Note that this is a significant under-representation.

I would be interested in reports of these species and other introduced ferns growing wild in New Zealand. This will help us better understand their invasiveness. Please contact me at leonp@tepapa.govt.nz, or 04 381 7261, or Leon Perrie, Te Papa, PO Box 467, Wellington.

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