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.

9 Responses

  1. grant

    thanx for the info and pics…i was trying trying to identify what i had in my back yard after uncovering it on a clean up…looked good so pruned it instead of pulling it!

    Reply
  2. Garry

    I am looking for a possible root stock of the solanum species to graft eggplant or tamarillos onto , very keen to find out more about poroporo / Kangaroo apple or any others you may recommend , many thanks. Garry

    Reply
  3. Carrie Colyar

    i have a potted one but am having trouble finding out how to care for this plant. What are its requirements? What kind of soil does it do best in and also water requirements?

    Reply
    • Leon Perrie

      Hi Carrie,
      Sorry, I don’t know much about growing plants, but I suspect that poroporo is fairly robust from where it grows in the wild. High light, well-watered (without flooding), reasonable and fertile soil, and temperatures 10-20C should be fine.
      Leon

  4. Leon Perrie

    Lucy:
    I haven’t given it a go, but will do so next time I see some ripe poroporo fruit.

    Andrew Crowe, in his book “A field guide to the native edible plants of New Zealand” describes the very ripe fruit as having “a very pleasant acid-sweet taste, something between a date and a tomato”. He describes unripe fruit (which were even orange, but didn’t have bursting skins) as burning his mouth and throat, even after only a small bite, so you do have to be careful!

    Yes, according to Crowe (who in turn cites an 1880 reference by William Colenso), they were eaten by Māori, and even cultivated around pā.

    Reply
  5. Leon Perrie

    Home stager & Auckland:
    It’s not that unusual. Fruit are often inedible before they’re ripe. Ever tried to eat an unripe apple, plum, or nectarine? Being poisonous is just taking it a step further!
    It is in the interest of the plant for the fruit not to be eaten by an animal until the seeds are fully developed. Hence, the fruit is good to eat only when it is “ripe”, and off-putting beforehand (e.g., too hard, or distasteful, even to the point of being poisonous). Ripening is often accompanied by physical change, including colour, as a “signal” to animals that the fruit is now ready (and safe) to eat.

    Reply
  6. Lucy

    Have you ever eaten a ripe poroporo fruit? Were they a plant food for Māori or just not poisonous?

    Reply
  7. Auckland

    This plant is an oxymoron of nature! I’ve never heard of an poisonous/edible fruit before.

    Reply
  8. home stager

    Wow how interesting, poisonous when green but edible when ripe? That’s is most unusual. This plant is a rarity, I can understand why people don’t care to have it around though.

    Reply

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