Art. LI.—-Notes on Certain Species of Carex in New Zealand.
[Read before the Wellington Philosophical Society, 13th February 1891.]
Carex glauca, Scop., Fl. Carn, ii., p. 223; Rchb., Ic. Fl. Germ., cent, vii., 269. C. recurva, Huds., Fl Ang., 413,. E.B. 1506.
This species was detected by Miss Kirk between Evans-and Lyall Bays, Port Nicholson, where it grows in large quantity,
and extends over several acres. About six years ago the habitat was fenced in, so that the vegetation has not been so closely cropped by wandering cattle as formerly, when the growth of herbage was rendered almost impossible. Now, however, the paddocks being but moderately stocked, several native plants which were formerly rare in this locality are to be found in abundance. Amongst them Schoenus nitens, Hook, f., may be specially mentioned, as it is almost as plentiful as the Carex with which it is associated, although for many years previous to the enclosure it was so extremely rare that not more than one or two stray specimens could be detected during the season. The grass is “self-sown,” the seeds having been deposited by cattle, so that it is extremely difficult to account for the introduction of the Carex; but it can scarcely be supposed that a plant generally distributed through Europe, North Africa, and Siberia would be restricted to a single habitat in New Zealand if really indigenous in the Southern Hemisphere.
The following description will enable New Zealand botanists to recognize this species should it be found in other localities
C. glauca, Scop.
A grassy, soboliferous species. Culms 6in.-18in. high rather slender. Leaves erect or recurved, ½in.—1¼in. broad, flat, glaucous, shorter than the culms, Spikelets 4–6, upper 3 male, female erect or nodding, ½in.—1¼in. long, with male flowers at the top, cylindrical, slender or stout, pedicels usually short. Glumes ovate, acute, with green midrib; perigynia obovoid or elliptic, slightly rough, exceeding the glumes, Stigmas, 3.
Carex muricata, Linn.
A plant doubtfully identified with this species owing, to the immaturity of the specimens is recorded by Mr. Cheeseman from Mount Owen, in the Nelson District, where it grows at an altitude of 4,000ft. Mr. J. Rutland, to whom I am greatly indebted for much information respecting the plants of the Marlborough District, has recently sent specimens of the large form of this species known as C. contigua, Hoppe, from a grass-paddock near Havelock. but it is to be feared that, although it has even a wider distribution in the Northern Hemisphere than the preceding species, it can scarcely be considered indigenous to New Zealand.
Carex leporina, Linn.
This species has been recorded by Mr. Cheeseman from several localities in the Nelson District, and was discovered by the writer at Ohariu, about fifteen miles from Wellington.
Recently I have received specimens collected, in the Pelorus by Mr. Rutland. But, notwithstanding the fact of its wide, general distribution in northern Europe, Siberia, western Asia, Greenland, the Rocky Mountains, &c, and its occurrence on both sides of Cook Strait, it must be considered an introduced species in New Zealand. It is believed to occur in the Falkland Islands.
It is plentiful in the British Islands, and its fruits are very likely to be introduced with badly-cleaned grass-seed.
Carex chlorantha, R. Br., and C. divisa, Huds.
As the first-named species was stated by the writer to occur in New Zealand,* it seems desirable that the reasons for erasing it from our lists should be fully stated, to prevent mistake respecting it in the future.
In 1871 I collected a Carex on the shores of the Waitemata which I was unable to refer to any species known to me. It occurred on a small flat at the base of the cliff, and covered a space of between thirty and forty square yards, forming a sward so extremely dense that it was scarcely possible to obtain rooted specimens with an ordinary pocket-knife. The leaves were as dense as a piece of pasturage, and the culms, from 4in. to 6in. high, but slightly overtopped the leaves, and gave the plant the appearance of C. arenaria, L., to which it is, indeed, closely related. During the next year specimens were sent to Kew, and- there identified as a variety of C. in-versa, R. Br., an identification which I was unable to accept. I then, forwarded specimens to my friend Baron von Mueller, who identified it with C. chlorantha, R. Br., and recorded it as a New Zealand species in his “Fragmenta.”† At that time works on Australian botany were not available for reference in Auckland, and there was no reason to doubt the accuracy of the identification; specimens were therefore distributed under that name, and some were deposited in the Museum of the Auckland Institute, where they remained at the time of my removal to Wellington in. 1874. A few years later I received a note from Mr. N. E. Brown, of the Kew Herbarium, stating that the plant “was not Carex inversa,” and, if not a form of C. colensoi, would prove to be a form, of C. divisa.” This, of course, was interesting; but on making a re-examination of my specimens I was convinced that the plant could not be referred to C. colensoi, and its general appearance differed so widely from that of any form of C. divisa known to me that, in the absence of authenticated specimens of C. chlorantha for comparison, I still continued to refer it to that species. Mr.
[Footnote] * Trans. N.Z. Inst. (1877), vol. x., p. 42, Appendix
[Footnote] † Fragmenta Phyt. Aust., viii., 256 (November, 1874).
Cheeseman, in his “Revision, of the New Zealand Carices” published in 1883,* stated that C. chlorantha had become extinct in the vicinity of Auckland, which, was not correct so far as the plant in question was concerned. On visiting Auckland in October, 1886, I made special search for the Carex, and, after some little difficulty, succeeded in finding it growing in the greatest luxuriance, but restricted to a comparatively small space on the lower part of the cliff. The coast-line had been greatly altered during the ten or twelve years that had elapsed since the plant was last seen by me, and the flat on which it grew in such abundance had been completely swept away, so that the base of the cliff was washed by the waves; but the plant still existed in considerable quantity. It had, however, changed its habit: instead of forming a compact turf with culms less than a foot in height, it formed loose open tufts with long slender nodding culms, some of which were over 2ft. 6in. high; the leaves were longer and narrower, the heads smaller. There was no difficulty in identifying it with C. divisa, Huds., and it was interesting to find the plant occupying a littoral situation similar to those which it chiefly affects in the eastern and southern counties of England. I subjoin a description to assist local workers in the event of its being found in other localities in the colony.
Carex divisa, Huds., Fl. Ang., 348, ed. i. E.B., 1096.
A slender tufted species, with stout, slightly-creeping root stock. Culms 1½ft.—2 ½ft. high. Leaves equalling or shorter than the culms, narrow, flexuous, involute. Spikelets numerous, bracteolate, forming a more or less compact head about 1in. long; male flowers at the top; glumes ovate, acuminate, perigynia plano-convex, almost orbicular, veined, with a minute bifid serrulate beak.
The bracts are filiform or setaceous, but the lowest never overtops the spike, as is commonly the case with English, specimens.
Distributed through Europe, North and South Africa, West Siberia, North-west India, Chili, &c.
There is greater probability of this species proving indigenous in the colony than either of the preceding, but further evidence is required. If introduced it must have been in the early days of settlement, to allow time for it to overcome the native vegetation so completely as to form a compact sward, and in that case it would be difficult to explain why it had not become more widely diffused in the Waitemata and elsewhere, as its utricles are produced in great abundance.
[Footnote] *Trans. N.Z. Inst., vol. xvi., p. 442.