Paul was asking if Dendrobium kingianum var. silcockii is still accepted in
judging circles.
Firstly the term "var. silcockii" is no longer accepted botanically, as it
is just a colour form of this variable species, having white tepals and a
purple to lilac stained labellum.
What has caused this controversy was a recent article in "The Orchadian"
that questioned the validity of the clone known as 'Bigfoot', and plants
bred from it. These have solid coloured labellums, higher than normal flower
counts, and larger than normal flowers. There are many that have questioned
in private if they are pure D. kingianum.
Personally I believe these plants are NOT pure D. kingianum, but are the
hybrid D. Gillian Leaney (Specio-kingianum {syn. D. Delicatum} x kingianum)
or D. Bicentennial Rose (Gillian Leaney x kingianum). However when
backcrossed onto true D. kingianum most of the progeny will closely resemble
the species. However, if you flower a number of them you will see some
throwbacks.
This is not new, for years some hybridists have been cheating by injecting
small doses of other related species into their "linebred" species programs.
It gives them hybrid vigour. Some examples include Dendrobium bigibbum,
Vanda coerulea, Phalaenopsis amabilis, Sarcochilus fitzgeraldii, Sophronitis
coccinea and Cattleya walkeriana (in particular the improved white
forms...how come they have tall slender canes and flower from the top of the
pseudobulb!!) are examples.
There is a big problem with many of the "Australian Dendrobium" hot/cold
types (or Tropicools if you like the trendy names) is that many hybrids that
claim D. bigibbum to be in the background actually have complex Phalaenanthe
dendrobe genes in there because they are superior horticulturally to the
native species. This is the reason why the countless remakes of hybrids like
D. Peewee (bigibbum x tetragonum) and D. Elegant Heart (Peewee x speciosum)
look NOTHING like the original crosses. That's because there is a foreign
(ie. Non-Australian) influence in those hybrids.
Now that has opened an even larger can of worms!
(I have been just lurking of late. My wife Louanne gave birth to a baby girl
- Rachael Lyn - six weeks ago, so orchid stuff has taken a bit of a
backseat. Hence my correspondence is now way behind!)
David P Banks
Editor: Australian Orchid Review
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