Journal Number 112
May 2009
THE COLUMN
Petalochilus "Gurdies"
By Eric Scanlen
Rudie Kuiter of Seaford Victoria, has a colony of Petalochilus "Gurdies" (Fig.39) a petaloid taxon
amongst Caladenia catenata,
in the Gurdies, some 90km SE of Melbourne. He has had them under
surveillance since 2004.
Rudie contacted the Column after seeing Kevin Matthews' pic of similar Petalochilus calyciformis in
J103:39.
Both have RS Roger's "linear appendage with sigmoid flexure, furnished with a little cup at the apex,
erect in front of the column" [1] (Fig.40) plus a petaloid labellum smaller than the other tepals.
Rudie's colony of P. "Gurdies" is similar too, and is intermingled with, normal Caladenia catenata (Fig.41).
Could it be that this trait of cup-on-stalk-and-petaloid-labellum (COSAPL) is a throw-back to an ancestral
form?
Some have suggested this and Hatch referred to the stalk-and-cup as the "staminoid appendage" [2].
It is possible that some section of the DNA is prone to accidental loss in these closely related little
Caladenia species,
thus producing similar mutations in at least three of them plus a Leporella.
| |
|
|
 |
 |
 |
| Figure 39 |
Figure 40 |
Figure 41 |
These four comprise
- Rudie's P. "Gurdies" clearly stemming from C. catenata,
- Kevin's P. calyciformis [J103:39] externally quite like C. minor (was C. aff. chlorostyla see J108:30)
- P. saccatus, similar to C. chlorostyla according to HB Matthews [3]. He wrote to TF Cheeseman on
28 Oct. 1912, "Casually it could be taken for the green-white," his apt reference to C. chlorostyla,
described 85 years later.
- WH Nicholls described teratological (the science or study of abnormal formations in organisms,
from the Greek for monstrous) specimens of Caladenia (Leptoceras) menziesii [4] with petaloid
labellum still retaining vestigial calli and column wings fused to form a cavity embracing the
lower two thirds of the column, which all sounds very familiar albeit in a different genus.
Is it also possible then that of these surprisingly consistent mutations, the first three can all be accepted
as belonging to the genus Petalochilus? If the "teratological" specimens can produce viable seed and
survive in their own right, why not give
them specific status?
HB Matthews wrote to Cheeseman on 17 Nov. 1912 that "plants seed freely" referring to Petalochilus
calyciformis and on
28 Oct 1912 that P. saccatus occurred "in three places in the one locality and as
much as a mile apart" [3].
A fairly clear indication of seed propagation in the Column's view.
Rudie Kuiter is intent on checking next year's crop of P. "Gurdies" for viable seed production.
There is no record of viability trials in the past for any of these four taxa, possibly because of the
peloric (regularity of structure occurring abnormally in flowers normally irregular, from the Latin
for monstrous) botanical label attached to them.
References
1. Rogers, R.S. Petalochilus - a New Genus of New Zealand Orchids Proc. NZ Inst. 56: 16-18, 1926
2. Hatch, E.D. Petalochilus Rog. and the New Zea-land forms of Caladenia R. Br. Trans.Roy.Soc.N.Z. 1949. 77: 398-402
3. Scanlen, E.A. Matthews and Son on Orchids NZNOG Historic Series No. 14, 2006
4. Nicholls, W.H. Vict. Natr. 61, 1945
5. St George, I.M. The Orchid Papers of E.D. Hatch, Historic Series No. 2 Vol. 1, 92, 1989
|
