Journal Number 95
May 2005

THE COLUMN

Gastrodia "long column black"
By Eric Scanlen

Pat Enright spotted some very dark Gastrodia in the eastern Wairarapa last year so took
a day off on 13 Jan 05 to visit the site (see his report p. 25 of this journal). Brian Molloy
thought they could be the same as illustrated in Dorothy Cooper's book [1] Plate 7, as
G. sesamoides (Fig. 31 below).

Pat's emails had the Column sitting up and taking notice. Regular G. "long column" s.s.
usually have olive green flowers with golden knobs on (tubercles) [J91 pp16,21,22] but
Dot's "dark green-black specimens with a long column as in G. sesamoides" which she
found on the Puffer Track on 15 Jan 83 [Newsletter 5 p1] are in the Column's index as
G. "long column black" pending closer examination.  Notice Dot no longer said there that
it was G. sesamoides.

Some of the G. "long column" s.s., in deep shade at Anderson Park Invercargill [J91:17],
were more of a dark brown but still had the same internal flower structure as the widespread olive/golds.

Dot didn't publish drawings of her Plate 7 [1] internal flower structure so the Column was in a lather for info. and speedily replied to see if Pat could check this out on his dark flowered plants. Pat emailed after his day off,

"The specimens I found could have been mistaken for G. cunninghamii from the colour. The flowers developed from the bottom and were hanging out and down. . . Not big plants, about 2ft high with approx 30 flowers. They grew under tall kanuka in good light" (Fig. 29 below).

On 22 Jan 05 Pat collected a few florets. The dark flowered specimen was growing up near
the top of the slope in a much hotter and drier area than one down in the gully (Fig. 30
below) just above the stream which Ian reckons is the same as the Bartons Bush taxon
(i.e. G. "long column" s.s.).

Olaf John's excellent photos, from which Fig. 29 & 30 were taken, arrived on 25 Jan 05,
thank you Olaf and Ian.

Florets arrived, thank you Pat, and were photographed 27 Jan 05 but they had not travelled
well. However, tantalising evidence emerged in the form of unjoined twin ridges of pseudo-
pollen - probably yellow originally but brown by photo time - under the labellum of
purported G. "long column black" (Fig. 28), similar to G. minor [2, p. 63, left form of
labellum] not forming the usual wishbone shape of G. cunninghamii, G. sesamoides and
G. "long column" s.s. (Fig. 27).

The dark one's twin ridges hang straight down as in G. minor and in G. "long column" s.s.
The ridges are not sloping evenly to the centreline as in the otherwise similar ridges under the labellum in Bruce Irwin's drawing of atypical G. cunninghamii [J38:7; 91:27 which the Column wanted to call G. leucopetala Col.].

   
 Fig 27                                                         Fig 28

Perhaps G. "long column black" is an hybrid between G. minor and G. "long column" s.s.?
That would explain the enlarged G. minor type labellum on a darkened but otherwise
G. "long column" s.s.  How about G. leucopetala Col. being an hybrid between G. minor and
G. cunninghamii?  That would explain the nonwishbone pseudopollen ridges on an otherwise G. cunninghamii plant.

What are your best guesses?  Do please have a look, oh gentle reader, to see if you have any G. "long column black" flowering near you, early in January and G. leucopetala Col. in early December near Rotorua and let the Editor know without delay.

     
 Fig 29                                     Fig 30                                      Fig 31

Acknowledgements
Many thanks to Pat Enright, Ian St George and Olaf John for forwarding material for this write-up.
Thanks also Brian Molloy for commenting on the orchid taxa and to Bruce Irwin for his incomparable drawings.

References
1. Cooper, Dorothy A Field Guide to NZ Native Orchids Price Milburn, 1981.
2. St George, I, Irwin, J.B., Hatch, E.D., Scanlen, E.A. Field guide to the NZ orchids 2001.