Journal Number 104
August 2007

THE COLUMN

Thelymitra fimbriata at Cave Creek
By Eric Scanlen

Steve Reekie wrote, "Here are a few more details about the Sun Orchid I found near Cave Creek.

"It was on the 23rd of December, a very sunny afternoon. I was on the track between Bullock Creek and Cave Creek, and found the orchid growing in full sunlight amongst grasses, not far from the edge of the track, just past the Cave Creek memorial and up the hill a little.

"The area is usually pretty damp there, even though it is on a hilltop, and the ground looked as though it was usually quite swampy, but at this time it was abnormally dry."

Steve's Sun Orchid is an unusual Thelymitra fimbriata Col. because of its white, not yellow, fimbria on the column arms. You may well ask, "What is T fimbriata?"

William Colenso described the flower in 1890 as "violet with dark pencillings..." and "staminodia [column arms] largely fimbriate..." amongst other details and his species is no doubt still legitimate today. T.F. Cheeseman commented in his 1906 Manual that it was "unknown to him" as most of Colenso's species seemed to be but Moore and Edgar, in the 1970 Flora, lumped T fimbriata into T. pulchella Hook. f

J.D. Hooker had in fact described T. pulchella, in his 1853 Flora, with "toothed or fimbriate staminodia" but in his 1864 Handbook he reverted to only "the toothed appendages of the column" with no mention of fimbria. The toothed form is common in the far north where Hooker would have seen it in his three months at the Bay of Islands in 1841. So Colenso was within his rights to describe one of the many fimbriated variants as T. fimbriata.

Colenso's, Hooker's, and Cheeseman's details were all gleaned from Ian St George's invaluable Historic Series.

Molloy and Dawson, in a 1998 Journal of Botany, depicted a fimbriate "T. pulchella" and showed convincingly that it was an amphidiploid hybrid between T. cyanea and T. longifolia.

All the Column's T. fimbriata from Kaeo to Te Anau, have yellow fimbria (except for the Albany lot which are tawny) but some unusual T. cyanea from National Park wetland (J80:18) and others from Tangiwai have white column arms not yellow. Perhaps one of these with white column arms was an ancestral, parent of Steve's Cave Creek specimens? Has anyone else spotted this taxon?