Wayne Cribb was kind enough to invite the Column to stay at his place, one of two houses still extant at Okahu. The Column jumped at the opportunity.

Okahu, which doesn't show on modern maps, is just 4 km due south of central Kaitaia where a derelict little church also marks the original village site. This is where Richard Henry Matthews started several field trips into the forest for orchid specimens to send to TF Cheeseman.

In RH Matthews' letters to Cheeseman, the most important finds up "the Okahu creek" (now Tarawhaturoa Stream) were RHM's "Okahu orchid" (Nematoceras rivularis) and "the lobed leafed one" (N. pandurata) which he found intermingled or in some places predominating, on the stream bank in view of the Okahu falls, visible from the Awanui Road.

The Column thought that perhaps N. pandurata was nothing more than a pandurate leaved form of N. rivularis because most or all of the +15 N. rivularis aggregate throw pandurate leaves at times so why wouldn't N. rivularis s.s.?

Cheeseman had nevertheless seen fit to make "the lobe-leafed one" the variety, Corysanthes rotundifolia var. pandurata as he called it, dutifully following Kirk [see Newsletter 17:4] who mistook a round leaved taxon at Big Omaha for Hooker's Corysanthes (Anzybas) rotundifolia.

Hold it right there! Kirk's in-flower specimen (WELT 18877) from July 1864 complies only with Nematoceras "Pollok" except it is too far north. The earliest flowering N "viridis" at nearby Sunnybrook Reserve was only in early bud on 2 Aug 2002. (there are photos!)

But in December 1866 (pers. comm. Dan Hatch) Kirk found another flowering specimen (WELT 18879) at or near the same place which, it seems, must have been Cunningham's Acianthus (Nematoceras) rivularis because no other of the aggregate flower so late. An expedition to check for these taxa in the streams running south from Tamahunga in the Omaha Forest would seem to be a NOG urgency.

The above is a simplification - truly - of the classification mix-ups involved. Readers can check the Editor's list, J97:11, for further intermediate nomenclature if they feel so inclined. Further to the above, as Dan also pointed out in N17:4, Cheeseman had long since labelled AK 3652, his own specimen of October 1873 from Titirangi, as Corysanthes rotundifolia var. pandurata.

He did not see fit to announce this in his 1906 Flora but gave the credit (or blame?) 52 years later to RH Matthews in the 1925 Flora for undoubtedly a different taxon! AK 3652 will be either Nematoceras "viridis" (alias whiskers) or N. "Kaimai" which both flower in the Waitakeres in October.

Confused? Read on, it gets better.

Flowers from both leaf forms looked identical as Cheeseman had noted in his 1925 Flora.

RHM's colonies would have been further upstream than this because he had had to negotiate a
rock face where he came a cropper on one occasion whereas Wayne's colony was still on bush-
clad flood plain with no view of a rock face or the waterfall.

Quite possibly, these lower stream reaches would have been modified before 1899 by kauri
hauling so that Wayne's colony might have recolonised and consolidated in the intervening
106 years.

Just upstream, the flood-plain petered out leaving a torturous ravine and still no view of the falls
to the daunted explorers with no rock climbing gear who returned whilst the going was good.

Brian Molloy has seen the photos and expects now that N. pandurata should be merged back into
N rivularis. (pers. comm.)

Later resort to the contour map showed that the falls were no more than 2km due south from Okahu. So, had RHM truly gone 5 or 6 miles thence, (letter 19 Sept. 1899) he would have gone right over the range, well into Diggers Valley. Perhaps it seemed like 5 or 6 miles in that rugged terrain?

RHM had indicated to Cheeseman that "The Rotundifolia (not Hooker's Corysanthes rotundifolia
which Cheeseman had renamed C. Matthewsii in error) flowers here first week in September."
Letter 8 Oct. 1900) and "the Okahu [Nematoceras rivularis] are practically two months later."
(letter 29 Oct. 1900).

So the Column was disappointed in not finding "The Rotundifolia" which he had posited as either
N "viridis", N "Kaimai", N "Kaitarakihi" or N "Pollok", none of which had been reported so far north and only N. "Pollok" flowers this early.

Another remote possibility is the New Plymouth, disjunct colony of N. rivularis which the Column saw in full flower in a park there on 22 Sept. 1993 but didn't realise what he wasn't photographing at the time. John Dodunski has kindly sent his pix of it and, apart from having a shorter pedicel and ovary and perhaps narrower labellum, this could have come out of Wayne's colony but why the notably earlier flowering time in a more southerly location unless it is RHM's "The Rotundifolia"?

Wayne spotted a small colony of rounded leaves 100m downstream of the big one on our way home but the flowers were unmistakably N. rivularis so the mystery remains.

Several times, RHM had mentioned an unusual blue Thelymitra to Cheeseman who forgot about
it, had to be reminded but still seemed not to respond to RHM's query.

Kevin Matthews, one of RHM's great great nephews, and friend of Wayne's, took the Column, on
22 Oct. 2005, to his Uncle Hackney's manuka (Leptospermum scoparium) wetland near Kaitaia Airport and pointed out some blue Thelymitra on tall, meandering and slender stems. They were tightly closed then but their columns (below centre) looked quite T. pulchella-like although the tepals were unstriped.

Kevin has since sent pix (photos left & right below) of some of these Thelymitra "sansfimbria" wide open and perfumed. Was this RH Matthews' blue Thelymitra? Who, among you dedicated readers will volunteer to track this one down?