Monday, 16 September 2013

Lindera has great looking nectaries


Fellow botanist, Neville Walsh, pointed out the fine nectaries of Lindera. It was a few weeks ago, and we were on a voyage of discovery through the Queensland Box Bed, not far from A Gate in Melbourne's Royal Botanic Gardens. This was just one of the plants with its assets easily overlooked.

Under a microscope, the nectaries are green and glistening, with a pair for each of the inner stamens (the male bits), and they seem to produce their nectar just as the anthers release their pollen. Normally nectaries attract pollinators to the female receptive part of the flower, the style, but in this case there no female bits. Lindera megaphylla is a species with male and female flowers on different plants.


Neville hypothesises (he calls it a guess) that the nectaries might look, smell or otherwise appear to be stigmas to a visiting pollinator. The released pollen probably sticks to them so might be picked up by this visitor and then transferred to a fully functioning female flower.

Across the other side of the lake, in what is sometimes called the Mulberry Bed, part of the southern Chinese collection, we later founds some girls. This time the stamens have been reduced to red-tipped appendages and there is a clear style in the middle of the flower. Also, as you can see, some glistening green nectaries. Not as many as in the males, interestingly, but still there to attract our potential pollinator.


We have four of the 80 or so species of Lindera growing in Royal Botanic Gardens Melbourne. Fittingly, they are all in the southern Chinese collection, with duplicates in odd places such as the Queensland Box Bed. All but a couple of Lindera species, from North America, are native to eastern Asia (i.e. primarily China): Lindera megaphylla is from wet forests at relatively high altitudes (1600-2000 metres above sea level) in southern and south-western provinces of China.


Just as appropriately, Lindera megaphylla lives up to its Latin species name and has big leaves. In China there are two forms recognised, one with hairless leaves (megaphylla) and one with finely hairy leaves or at least leaves with finely hairy veins (touyunensis). Our leaves seem devoid of any downy covering.

Neville and I will have to mount a follow-up expedition to the Mulberry Bed in a month or two, looking for fertile fruits to see if there was any across the botanic gardens pollination. We can then crush a fruit or two to smell the reputedly aromatic oil, and to clean our hands (it's used in China to make soap).


1 comment:

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