Journal Number 103
May 2007

THE COLUMN

Caladenia "2 Leaf" at Kaitaia
By Eric Scanlen

Kevin Matthews found two Caladenia-like leaves on one plant, at his farm near Kaitaia on 5 Sept 06 and emailed pix to the Column even before a bud had emerged. This was only two days before he spotted the leaf and shovel shaped, translucent spathe on Petalochilus calyciformis(?) plants (following article).

But the twin leaves were emerging from a tubular spathe, (or sheathing bract, as Colenso described it) at 90° to each other, covered sparsely with fine hairs, slightly Veed and with 4 red ribs below.

The Column replied, patiently, that Caladenia have only one leaf but Kevin knows his Caladenia leaves and kept a close watch on developments.

A peduncle emerged seemingly painstakingly slowly, first displaying opposite paired bracts then four Caladenia-like swelling buds, covered in red glands like C. aff. chlorostyla but with red midribs at the base of each sepal.

Kevin had of course hunted around and had found a few more of these unheard of plants in another area, just to prove that number one wasn't an isolated freak. Finally four distinctly Caladenia flowers burst forth in opposite pairs (Fig. 30) displaying a double-plant form of mutation, no doubt to C. aff. chlorostyla to which it bears a close resemblance.

How do the flowers differ? C. "2Ieaf" has the red bases to those dorsal sepal midribs and white tipped disc calli, not yellow, it has the green stem of one form of C. aff. chlorostyla but the three red ribs to the green ovary of the red stemmed form, sepals are obtuse, canoe-prow and the dorsal sepal clings to the column in fresh flowers much as in C. aff.pusilla.

These characters are well displayed on the cover of J102 remembering that this plant had only a solitary leaf and bract but did have the requisite four flowers. The fact that there are more of these two leaved plants does infer that they are seed propagating because Caladenia do not normally spread vegetatively, do they?

Just to complicate matters, C. aff. chlorostyla is growing nearby and several in-between plants have flowered, all with slightly different flower, leaf and bract arrangements with flowers numbering 1-4. They are most likely hybrids between C. "2Ieaf" and C. aff. chlorostyla.

C. "2Ieaf" is quite sparse on the ground so it is interesting to speculate that its unusual genetic makeup may finally be eclipsed by this putative back crossing with parents and hybrids unless it displays some cryptic dominant characters that will let it increase as a separate taxon in the age old ways of evolution.

C. "2Ieaf" is the first unusual orchid taxon that Kevin has found that neither of his relatives, RH & HB Matthews reported around 100 years ago. There is another of Kevin's, a two leaved, long stemmed, late flowering Thelymitra that may rival one of RH Matthews'. a colony of short stemmed, two leaved Thelymitra which also flowered late on 5 January 1903 [1. p38].

The Column didn't know what to think about two leaved Thelymitra when compiling that booklet any more than Kevin's two leaved Caladenia on 5 Sept 06. However, the truth has proven stranger than fiction and Kevin's colony of eight two leaved Thelymitra will undoubtedly be the subject of another paragraph when it finally flowers.

Reference

1. Scanlen, E.A. Matthews and Son on Orchids