It was on the Naturewatch website, and someone had posted a photo with a request for identification. I thought it looked like puha (Sonchus oleraceus), but then I changed my mind and identified it as Cape weed, Arctotheca calendula. The great thing about Naturewatch is that the identifications are crowd-sourced, and others quickly challenged my identification and convinced me, with evidence, that I was wrong. The plant was indeed puha (Sonchus oleraceus). (It's a bit embarrassing, because I wrote the Flora of New Zealand treatment for both these plants.)
So yesterday, I went looking for some fresh material. Here are the upper surfaces of the leaves:
Cape weed (left) and puha, upper surfaces (scale=1cm) |
Cape weed (left) and puha, lower surfaces (scale=1cm) |
Of course, it'd be hard to confuse them in flower, but early growth is often the time when foragers collect, because some plants get bitter when they run to flower.
Cape weed (left) and puha in flower. |
The moral of the story is that identifying plants from photos can be difficult. Often the diagnostic characteristics can't be seen and sometimes the colours recorded in a photo don't look the same as in life. Plant taxonomists (specialists in the classification, naming, identification, and evolution of plants) often refuse to identify photos, but I believe that so long as people understand the pitfalls it's worth having a try. I really like the Naturewatch site, because it's self-correcting, democratic (everyone can have a go), and we all learn something from participating.
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