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Journal Number 88
September 2003
THE COLUMN
Petalochilus, Prasophyllum, Stegostyla Round-Up
By Eric Scanlen
Stegostyla lyallii "4row" twin flowered (Photo right)and single flowered, greeted the TAT (tackle-anything-trio), Gordon Sylvester (Puddy TAT), Mark Moorhouse and the Column at the frontage to Dennis Meade's bach, St Arnaud on 29 November 02. It was not a metre from the white Singularybas "aestivalis" site.
This is mossy, glacial moraine, on the Brunner Peninsula, in regenerating beech/kanuka forest, where DoC requires conservation of the grounds; no lawns! Great habitat for orchids, thriving on the bush edges, around the bach and on the frontage up here at 660m altitude.
The Column wanted to compare southern S. lyallii taxa with the numerous forms at Iwitahi [J78 centrefold], and here was one with 4 rows of disc calli, wide, 5 veined tepals, sparse red glands on dorsal sepal hairs, red stem and green ovary. Compare J78 p113, the Column's non-red barred S. lyallii, with 2 rows of disc calli, narrow 3 veined tepals, red stem (so it is not an albino) and red glands, both sessile and on hairs atop the dorsal sepal.
Both had sessile, marginal calli to the midlobe hence they comply with David Jones' definition of
S. lyallii [ref 1; J61:6-8; J63:41 but the tedious truth is that these two specimens have separate characters so they are separate taxa, aren't they?
Hooker in his 1864 Handbook, originally described Caladenia lyallii as "disk with 2 series of stipitate glands" as drawn by Dr Brian Molloy [1]. So it would appear that the Iwitahi alba form, plus a red barred one the Column has from Tongariro's Ketetahi track, 1978 [J59:12] are S. lyallii s.s. And the 4 row, 5 veined taxon at St Arnaud, also lacking the sessile glands on the dorsal sepal, isn't!
Thus it came to be tagged Stegostyla lyallii "4 row" despite Cheeseman and most subsequent chroniclers insisting in error, that there should be 4 rows of calli on the disc. What do you think?
Stegostyla aff. alpina, twin flowered and aging (Photo left), greeted the TAT in the identical place to the S. lyallii, at Dennis's frontage; but 21 days later. Who wants these enigmas on a restful (?) S.I. holiday? By lying, lens-in-hand in the gutter, as he does, the Column found it was not the 29 Nov 02 twin flowered S. lyallii "4 row" whose remnants were later uncovered.
One puff of hot breath neatly hooked a labellum down, by its marginal calli, between the lateral sepals, showing off the 6 irregular rows of calli reducing to 4, of S. aff. alpina. The slides later showed a different pattern of red stripes inside the column and marginal calli (not noted on site!) at the pucker where lateral and mid-lobes meet, so it was a different plant. A most confusing coincidence.
At Arthur's Pass, Dobson Nature Walk, 7 Dec 02, S. aff. alpina with maroon stems and green bracts, were not uncommon but Gloria spotted a twin with 4 rows of calli in the fresh, top flower and 4 + 2 half rows in the lower, more mature flower (Photo right) much as Mark had reported in J78:21.
The mature one was open enough to view, against its own leaf
(Photo lower-right). How come? The long stem fell over at an
insect bite, honestly! Note the length of the leaf hairs. |
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This taxon is a twin to the St Arnaud one above also to J82:16 (Ian St George's from Dunedin),
and J78 Plate 1 (Mark's at Mt Robert) so it is a widespread
taxon which could well earn specific classification. The Tasmanian S. alpina flowers at the same time but has narrower tepals together with red buds and bracts.
However, the similar but smaller Iwitahi taxa, J35:20 of Max Gibbs's and J78 Plate 9, the Column's
alba form with red stem, don't quite fit and there is a stepped midlobe form too: all three the
Column is tentatively lumping as S. "subalpine". Iwitahi's widespread little S. aff. lyallii [J76:39] and
S. "lytuck" [J78:35] a form with tucked back column wings, are in there as well but separate again.
If the above leads are borne out by DNA analysis, it seems that S. aff. alpina [J76:39} and S. lyallii
"4 row" [Fig. 1] do not occur at Iwitahi. Also, the Column's Journal index is in for some serious amendments as are some of his cherished mental type specimens from way back. What do you think?
Petalochilus aff. chlorostylus red stemmed and twin flowered, opened on track-side near Dennis's bach on 22 Dec 02, our last day at St Arnaud. A late afternoon effort achieved the Photo on the right. At first we thought (were sure!) it was multi-flowered P. "red stem", first reported by Gordon from the Puffer Track, [J39:12] then by the Column and field party from the same area [J66:25] as Caladenia "maroon".
The Puffer taxon had 2-4 flowers per spike and everything maroon, bracts stem, ovary and buds. But Bruce Irwin's P. aff. chlorostylus [J79:6; J83:17] sometimes throws two flowers as Robbie Graham (pers. comm.) has photographed at Iwitahi, it can have red or green stems but the red-stemmed form has three green strips on the ovary [J83:16 Fig. 2 of Bruce's & J86:32 of the Editor's] just like the St Arnaud specimen - which thus triggered the Column's re-identification of it as P aff. chlorostylus. |
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The St Arnaud specimen survived the close attention and leg numbing photography, you will be
pleased to know, but, as always before, the Column photographed it from the front (lower-right),
so the only red glands showing on sepal backs, are peeping around the sepal tips or on the out-
of-focus bud: not good for a principal identifier.
 Post script. On 18 Nov 93, at Albany Scenic Reserve, Doug McCrae identified what we now call, P. aff. chlorostylus, both with red and green stems, as his Caladenia "green column" [J35:32-43].
The Column photographed only the pretty red stemmed ones that day and featured one in "The Caladenia minor imbroglio" [J72:27 Fig. 2] as his quintessential Caladenia minor; please note! Like Doug, he had lumped all the northern taxa with toothed midlobes, into C. "green column".
Bruce, it transpired, was well aware then of the hairy vs. glandular sepalled distinction between the all-green-tepals-and-stem, P. minor/ chlorostylus and later flowering, red or green stemmed P. aff. chlorostylus, to use their modern classifications.
Doug had been aware of Bruce's split, Brian Molloy and the Column had also been told but none
of them had twigged. It wasn't until Bruce published a description and tagged his red glanded taxon as P. aff. chlorostylus, in J83:17 last June, that the Column caught up with the consistent differences between these taxa in his own numerous pics of them.
BUT, we still do not know whether Hooker's type specimen of Caladenia minor, held at Kew, has hairs or sessile red glands on its sepal backs. In other words, is Caladenia minor, Petalochilus chlorostylus or Bruce's P. aff. chlorostylus? Next time you are in London, pop out to Kew, have a look and do please let us know.
The moral of the postscript is, when you notice a consistent difference in a taxon, please focus attention on it by tagging and publishing it yourself.
Petalochilus nothofageti (Molloy), was by the same track as P aff. chlorostylus but nearer the bach,also on 22 Dec 02; a rare sight for the Column.
In Photo right it has its long, bright green leaf tucked under, showing sparse, short, non-glandular trichomes (hairs) on the right edge, viewing the slide with a X20 lens.
Those trichomes were supposed to be glandular and the leaf shouldn't reach past the flower according to Brian Molloy's description and drawing [2] so there is some variation within the species. |
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If it weren't for the colour, it could come off the same plant as P aff.chlorostylus! It even has sessile, but colourless glands on the sepals. P. minor / chlorostylus also opened this day on the Peninsula Nature Walk, confirming the start of the Petalochilus season just as we were leaving.
Prasophyllum "A" (Photo below-left), 15 Dec 02, from Jacks Pass at 869m altitude near Hanmer Springs, has conjoined sepals. At first it was mistaken for P. colensoi, but the moderately long column arms and widely spaced larger flowers, clinched its I.D. Pollinia like bunches of grapes (similar to P. "B") have mostly gone but some "berries" remain.
On 20 Dec 02, another P. "A" at 1000m on Mt Robert, looking out over L. Rotoiti, had free lateral sepals. Both were green form [J79:9] in contrast to the purple scaped specimen from Middle Road [J87:6, Fig. 1]. For comparison, Photo below-right is the closely related P. colensoi from Takaka Hill on 27 Nov 02. Note the short column arms with tips barely showing.
 
Conclusion. Vigilance for Drymoanthus on Gloria's and the Column's tour of the South Island top half, was rewarded with one out- of-reach D. adversus at Lake Kaniere, but we were too early on Brunner Peninsula for Gastrodia "long column St Arnaud" and an all-dark purple Thelymitra sp. In bud along the roadside or for Hymenochilus tanypodus anywhere so another S.I trip is a must in the near future.
The orchids encountered were well above expectations making for an enthralling trip, thanks in no small part to Thom Pendrigh and Hazel, Mark & Caryl Moorhouse, Cherry & Gordon Sylvester and to other keen members of the field trip to Rainbow Skifield.
References
1. Jones D.L., "Reinstatement of Caladenia alpina RS Rogers as distinct from Caladenia lyallii Hook. f. etc."
Muelleria 9:41-50.
2. Jones D.L., Molloy BPJ, & Clements MA, Three New Species and a New Combination in Caladenia R. Br.
from NZ, The Orchadian 12:5, Sept 1997, 221-228.
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