Art. XVIII.—On the occurrence of Orobanche; a genus new to the Flora of New Zealand.
[Read before the Auckland Institute, September 20, 1869.]
Mr. Robert Mair, of Whangarei, has favoured me with a specimen of an Orobanche, discovered by him, and from the interest attending the first discovery of a Broom rape in this colony, I venture to make a few remarks upon the specimen so kindly sent, chiefly with the view of directing the attention of other botanists to the genus.
The specimen is unhappily in a bad state of preservation, having suffered considerably from the attacks of insects, so that it would not be safe to attempt a diagnosis until better material can be procured. From the solitary bract, and sepals narrowed into subulate points, it evidently belongs to the group of which the European Orobanche minor, which is commonly parasitic on the roots of clover, may be taken as the type, its nearest ally appears to be the O. Picridis (F. W. Schultz), from which it differs (so far as can be judged from the condition of the specimen), in more robust habit, more numerous and closely aggregated flowers, wider bracts, which become much elongated after flowering, in the broader sepals, which are shorter than the tube of the corolla which is more erect, and less ventricose at the base, with narrower tips.
Mr. Mair informs me, “that the plant grows on a sharp ridge, which has never been broken up, and is covered with Pteris esculenta, and a few scattered plants of hawk-weed.” It is probably parasitic on the roots of the hawk-weed.
In the southern hemisphere, this genus is found at the Cape of Good Hope. A solitary species, O. cernua (Loeff.), which is also a Mediterranean plant, is found in Australia, where it is chiefly parasitic on the roots of Senecio lautus.
It might be worth while to search for other members of this genus at the roots of our various Araliads, especially of Panax Colensoi, and P. Lessonii, in hilly districts.