Monday, 22 August 2011

Pittosporum cornifolium

These orange fruits with black seeds caught my eye as I was walking up the path beside the Students' Union building.  The orange colour isn't a fleshy aril, but simply the inside of the capsule, and it serves to highlight the sticky black seeds.  Is it a mimic of other plants that present black seeds on a fleshy orange or red structure (podocarps, Alectryon, Ixerba)?  If so, it's getting its seeds dispersed for the small cost of a bit of orange pigment instead of the energy rich epimatium of a podocarp or aril of Alectryon or Ixerba.

There were tuis nearby making quite a racket, but they were disputing in a flowering P. crassifolium tree that was interleaved with a flowering puriri (Vitex lucens), so it was more likely nectar they were interested in.

The epithet cornifolium is a reference to the leaves of the dogwoods, Cornus, which are also in whorls of four.  Here's Cornus canadensis in the grounds of the University of New Brunswick, Fredericton, Canada.

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