Journal Number 108
May 2008

THE TYPE LOCALITY

Puehutai and Nematoceras rotundifolia
By Ian St George

In J38 (1991) Dan Hatch wrote that Corybas (Anzybas) rotundifolius appeared actually to be what was then known as C. aff. unguiculatus, and not (as had been supposed) a synonym for Corybas rivularis agg. or Corybas oblongus.

The lectotype had been determined by Mark Clements as Colenso's specimen #740 at Kew – a collection of 12 orbicular-apiculate leaves, one with an unopened flower. Clements thought the specimen was likely to be Corybas (Anzybas) carsei or C. aff. unguiculatus, and sent a photograph to Hatch, who determined its identity from the photograph. He sketched the outline of the flower (left).

Colenso's note in his July 1846 letter to WJ Hooker says:
"740. Orchis, - sides of clayey hills, Puehutai, R. Manawatu; - only 1 in fl. - I can get more - leaf struck me as being new".

He had by 1846 collected a number of specimens of "Acianthus" - members of the Nematoceras trilobum and N. rivulare aggregates - so he knew this leaf was not of one of those.

Hooker's description

JD Hooker described it thus: "caule elongato, folio rotundato cordato apiculato, scapo ex axilla folii orto brevi, bractea ovario aequilonga" (stem long, leaf round, heart-shaped, pointed, scape from armpit of leaf straight, short, bract as long as ovary) "I regret not having expanded flowers of this curious little plant; those I have in bud resemble N. oblonga in size and form of the pieces of the perianth. Stem slender, 1-2 inches long. Leaf orbicular, cordate, acuminate or apiculate, ½ inch broad. The flower rises from between the lobes of the base of the leaf in my specimens, but this may not be a constant character." (Hooker wrote "those" and "specimens", which suggests he had examined more than the one bud from #740, perhaps of other taxa). "Hab. Northern Island. Clay banks."

He expressed his uncertainty about the plant, for he then wrote "I have leaves of this or a very similar plant from Lord Auckland's Group", and later listed its localities as Manawata Harbour (sic) etc, Nelson, Lord Auckland's group and Campbell's Island. "Perhaps a variety of C. oblonga".

Where and when did Colenso collect it?

Colenso wrote to WJ Hooker that he collected the plant on 2 April 1846. The entry in his Journal for 2 April tells us he had spent the preceding night in Otawao; it goes on, "Started at 7, travelled to Puehutai, another small village about 1½ miles from Otawao…. Resuming our journey, 3 hours travelling brought us to Te Hautotara, another small village, and the last, upon the upper part of the River Manawatu".

Otawao was on the west bank of the Manawatu river, south of Dannevirke, south of the Otawhao-Manawatu confluence, between Kumeroa and Dannevirke. Puehutai was on the river, just downstream from the loop opposite Oringi – i.e. a few miles south of Dannevirke; above Puehutai the river was shallow and no longer navigable. Hautotara was south of Dannevirke at the Mangatera-Manawatu confluence.

Colenso had spent 2 April 1846 walking upriver on the south bank, crossed to Puehutai (his journal entry for another visit on 29 Sep 1846 says "Crossing the River Manawatu on a native's shoulders… arrived at Puehutai"), should have recrossed a little upstream, to take a short cut and thus avoid backtracking around the loop to the north of Puehutai (the walk to Hautotara took 3 hours in April, and 2 ½ hours in September – almost impossible if he had backtracked). The river and the flats were again to his left, his direct path to Hautotara skirting the foothills of the Puketoi ranges to his right (see map).
If indeed this was when Colenso found the orchid, my bet it was on the clay foothills to his right.

Other plants collected nearby and listed on the same page in his letter, were no. 744 ("banks R. Manawatu"), 745 ("near Puehutai"), 746 ("Banks River Manawatu"), suggesting a consistent sequence.

The dots show the likely start of Colenso's walk from Puehutai toward Hautotara on 2 April 1846,
when he collected Nematoceras rotundifolia.

Wrong, wrong, wrong

Time and place and habitat are all out of joint. The latitude and the flowering time are wrong for Anzybas rotundifolius, which until its recent discovery on the Chatham's, and apart from this Puehutai discovery, has been found only north of Warkworth, flowering June to August, and never on clay hills.

Hatch wrote, "specimens in herbaria suggest that it once extended much further south" but I know of
no other specimens from south of Warkworth. These were cold years (the Ruamahanga river in the
Wairarapa had frozen over the winter before, according to entries in Colenso's journal, and he wrote
from Hawkes Bay in August 1846, "It is very cold here – water freezes in our Chamber, and milk in
the pantry!"), and April just seems too early and the Manawatu too far south.

Could the plant be something else? Hooker's description could fit several species, but of all the candidates, only Corybas cheesemanii flowers in April (or, most unlikely, a vagrant Australian Anzybas unguiculatus which flowers early and grows as far south as Tasmania). Hatch's drawing could be a bud of Anzybas rotundifolius, and though it also bears a resemblance to Corybas cheesemanii, the leaves are wrong.

		Fig. 2 (IFC) shows the restored solitary flower bud (January 1989) of the holotype of Hooker's Nematoceras rotundifolia (and it is unequivocally an Anzybas) collected by Colenso (740) from "Northern Island. Clay banks. Manawatu." ( courtesy of Brian Molloy ).
Figure 2
		Fig. 3 shows the specimen enlarged from the type sheet, which is itself shown in Fig.4 (below). Why did Hooker suggest he had examined more than one flower?
Figure 3

The Type sheet for Anzybas rotundifolius carries several specimens, and only #740 has been designated the lectotype. Note the 11 leaves (and a seedpod?), as well as the single flower in the separate envelope at upper right. The other specimens appear to be members of the Nematoceras macranthum or N. rivulare complexes, long thought to be the true inheritors of the specific epithet "rotundifolius".

What is at the type locality today?

Today the river is marked by a row of willows, and the hills rise above rich sheep land, but their raw faces are clayey, a layer of yellow clay on top of soft mudstone, full of fossil shells.

The river is low after the drought, barely above my knees as I cross. Barkers, dotterils, black swan, paradise duck panic at my approach. An angler is landing a 2lb rainbow at the corner of the river. He asks what I am looking for, and I tell him an orchid. He scratches his head, "Gee, an orchid. I don't think so. I don't think you'll find orchids here. Look around: there are no native plants at all."

The Oringi loop of the Manawatu river, photographed from the hills to the west.
Puehutai should have been on the elevated river terrace in the centre of the loop.

Clay banks of grey sedimentary mudstone, full of fossil shells - not volcanic papa.		Colenso's path from Puehutai toward Te Hautotara ran along these now bare hills; if these were the "clayey hills" where he found the orchid, it is not there now.

He is right: an odd totara and cabbage tree survives, but every piece of land is farmed.

Colenso replied to an enquiry from Cheeseman in a letter dated 25 Dec 82: "... were I there, or at ...
‘Puehutai,' I doubt if I could find a single plant in its old haunts. Sheep & Cattle, - Clover, Grasses,
Weeds, and Fires, have effectually done their work of extermination."

Puehutai must have been on the raised old river terrace above the flood level, in the middle of the omega-shaped river bend.

I didn't see an orchid all day. Colenso's Nematoceras rotundifolius must remain a puzzle.