Art. XLII.—On the Genus Corallospartium.
[Read before the Philosophical Institute of Canterbury, 5th August, 1880.]
The singular Papilionaceous plant known to the settlers of Canterbury as the coral broom, was included by Sir Joseph Hooker in Brown's genus Carmichælia, and described as Carmichælia crassicaulis in his “Handbook of the New Zealand Flora.” Even prior to the publication of the handbook however, I had always doubted whether the plant was really referable to that genus, and often since that time the doubt has recurred to me. I have therefore been induced to go fully into the matter whilst arranging the species of Carmichælia for my work on the New Zealand flora, and having examined an extensive series of specimens in the hope of being able to come to some definite conclusion, I have now decided to separate the plant from that genus, and to adopt for it the name Corallospartium, as the pods and flowers seem to me to present as good distinctive characters as many other accepted genera. Our new genus comes nearest Carmichælia, from which it is readily distinguished by the compressed one-seeded pod, splitting into two valves, and the fascicled woolly flowers. As far as I have been able to ascertain, the genus is in no way related to any non-New Zealand genus; it may be described as follows:—
Corallospartium crassicaule, Armstrong.
Carmichælia crassicaulis, Hk. f.
A straggling, erect, or sub-erect or decumbent shrub 18 inches to 3 feet high, rarely more. The branches and branchlets are dark green, and densely pubescent when young, glabrous and straw-coloured when old, obtuse, very stout, ⅓–1 inch broad, terete below, much compressed above, deeply channelled in parallel lines. The leaves are trifoliate or quinqui-
foliate; the leaflets linear, oblong, or oblong-obtuse, shortly stalked, pubescent, ¼–½ inch long, very often altogether absent. The flowers are ¼–⅓ inch long, arranged in dense, globose, axillary fascicles which contain 10–20 flowers. The pedicels are about ⅛ inch long, slender, densely-clothed with soft grey hairs. The calyx is campanulate or cylindrical, ⅙ inch long, densely woolly, obscurely two-lipped, with two short subacute teeth in the upper lip, and three similar teeth in the lower lip. The standard is broadly orbicular or oblong, ⅓ inch diameter, much reflexed. The wings are narrow and much shorter than the keel, oblong, auricled at the base and turned upwards.
The keel is nearly ½ an inch long, oblong, obtuse, and turned upwards at the point. The stamens are 8–10 in number, the filaments extremely slender, the upper stamen free, the others united into a tube from above the middle and sheathing the ovary. The style 1, much stouter than the stamens, woolly at the base with the point turned upwards. Both the style and the stamens are enclosed in the folds of the keel. The bracteoles are minute, woolly. The pod is about ¼–⅓ inch long, deltoid or triangular in outline, splitting into two valves, much compressed, one-seeded, coriaceous, with the surface distinctly reticulated, prolonged above into a broad rounded wing, below into a short, sharp, straight beak. The seed is oblong-reniform, dark brown, ⅛ inch long, with a slightly thickened funicle, and double flexured radicle. Ovary villous with white hairs.
Hab.—The Corallospartium is found in numerous localities in the alps of Nelson, Canterbury, and Otago, at altitudes varying from 2,000 to 5,000 feet, but is most common in the Canterbury Provincial District at about 3,000 feet. It is nowhere very abundant, and is rarely found in fruit. I think it is very probable that other species of this genus will be discovered, as there are doubtless very many new plants yet to be found in the South Island.
None of the numerous specimens examined show any important variations, and it appears that the New Zealand species of Papilionaceæ are generally much less variable than any other order of the same extent. The difficulties experienced by students of the genus Carmichælia arise more from the sameness of the species when dried than from any great tendency to vary. I have carefully examined large numbers of Australian Papilionaceous plants, but have found none of them in any way resembling this either in flowers or pods, and indeed it seems very certain that there is but a very slight relationship between the Australian and New Zealand Leguminous plants. Indeed the connections between the floras of New Zealand and Australia have been very much exaggerated by all the writers who have yet paid attention to the subject.