PLANTS OF THE DUNEDIN DISTRICT.

Otago Daily Times, Issue 19197, 13 June 1924, Page 5

PLANTS OF THE DUNEDIN DISTRICT.

XI. —THE RUSHES, SEDGES, AND GRASSES. Written for the Otago Daily Times. By William Martin, B.Sc. THE RUSHES. Though quite a small family, the true rushes—.species of Juncus —are well distributed over tho globe. Of the 16 species indigenous to New Zealand, one half aro represented locally, and these are supplemented by many other plants popularly designated rushes, as tho wood rushes (Lunula), tho twig rushes (Cladium), the spike rushes (Eleocharis), and (he bogrushes (Seirpus). It is not easy to say in non-seientifie language just, what a rusil is. but the. round stems and loaves, and distinct (lowers followed by a shining, dark, hard, glossy “ seed” are fairly constant features. B edges have flat leaves forming three rows along tho culm or stern, while in grasses tho loaves are arranged m two rows. Rushes usually but not invariably inhabit damp, poorly drained land, and of these the Maori wi-wi (Juncus elTnsus) is easily the most abundant. The tallest native rush, J. pallidas, grows very sparingly near the base of the Sandspit at Otago Heads. Locally it. is under sft in height, but in Stewart Island or on Chatham Islands^ it may reach to almost twice this height. Tho nearest approach to this in size is made, by J. vaginatus, a densely tufted, stout species almost con lined to coastal stations .and formerly growing also on the Bp it. Juncus pauoiflonis, though not previously recorded, is common in dry places such as the golf links at St. Glair or the Domain at Brig’hton and may be recognised from its thin, few Cowered stems and laxly tufted habit. Tho toad rush (J. bufonius) scarcely resembles any other rush, but is exceedingly abundant o'n tho sides of ditches and even in gardens. In somewhat damper places tho flat-leaved J. planifolins may more often be seen bearing a loosely branched panicle of dark “ seeded ” flowers. J. cseapiticius is met with very sparingly on Opoho Hill near the cemetery, and is best recognised by its leafy habit and by the globose head which crowns the naked flower stalk; Another leafy species of more slender habit, common in many countries of the Northern Hemisphere, has been reported from Sawyers’ Bay, but 1 have not verified this record. Our last species is also least in point of size, seldom exceeding two or three inches in height and bearing one or two shining black nutlets near the top. This plant (J. novaa zcalandioe) is not uncommon on Flagstaff and generally in damp spots at some elevation above sea level. The wood rush (Luzula campestns) is a plant of almost world-wide distribution and innumerable fcims. Lccally, two varieties, var, piotn and var. austi alasica occur, which, like all other forms, aro grassy plants with leaves fringed with long hairs and terminating in blunt, thickened tips. The bulrush (Typhai no longer occurs so abundantly as formerly, but suitable places still finds a home, as at Tomahwit and tho head of the harbour. The stnkernshes resemble nothing so much as a spear Their scientific name of Eleochaens is de rived from Or. “ helos,” a marsh; and “chairo.” I rejoice. The common E. acuta grows mostly rear tho sea, but the much more slender E, Cimninghamii grows near tho western summit of Flagstaff, where it has previously been overlooked. Both these and the mud-rushes so-called, are in reality =ed<res in spite of their popular names. The ioitiled rush Leptocarpus is exceedingly abundant in all tidal lagoons round our coastline, and has already received notice. SEDGES. These plants include all the well-known cutty-grasses (Carex), which, of couise, aio in reality not grasses at all. and also the twig-rushes (Cladium). which likewise are not rushes. Perhaps this will serve to show the non-botamVal reader how real isi tho necessity for definite scientific names. Duito a number of alp-’ne and bush sedges have already been referred to—e.g.. the cuU\ .rruss of the sand-hills, the Carpha and Oreobolus of • Maungatua, various hooked sedges (Uiicinia), and several species ot The square-stemmed twig-rush (Cladium Vauthiera) is met with on Flagstaff. Lookout Point roadside, Kaikorai Mouth, and manv other places, while its round-stemmed congener (C. glomeratuui) is to he found on Signal Hill and on Flagstaff. The false snow tussock (Schoenus pauciflorus) is known to me only from Maungatua, a patch of what I had formerly regarded i. 5 such at Whare Flat having proved on investigation to be a tall, rush-like, hooked sedge Uncinia stnctissima not formerly known from this neiglibouriiood. very wire, erect, and slender relative, a. nitei’s with a small few-seeded head has been noted at the Heads, whore it seldom exceeds 6in in height. Seven -pccics of Bchpus occur ranging from the large Scirpus nmritimus with its thick triangular stems, grassy leaves, and Ini'!/*? brown spiktilcts to ibo dinnnutivG o. ceriums, one of the commonest plants near the base of coastal cliffs and banks. fe. aucklaiidicus and S. inundatus are very similar fresh water representatives of Bwampv Hill and Maungatua, whi,e o. nedosus is a tall, harsh, rush-like representative commonest on the sand hills. Growing in S ;dt water in coastal lagoons one qmto frequently meets with another form S. Aniencanus, which has green, conspicuously triangular stems and a single spikele.l, an inch or two from the top. This plant ranges over Europe, North and South America, and Australia as well as over New Zealand. Of the hooked anemias several nave already been mentioned. An exceedingly on Mount'Cargill, is well named Uncinia filiformis, and two others, with stronglytinted stems and leaves, confined to theopen country above the bushbne, arc appropriately named U. rubra and U purpuvata A species with long slender seed stalks and iong narrow leaves occurs in scrub on Signal Hill and elsewhere, 'mown ns U. lepiostachya. and greatly resembles a sedge growing commonly in the bush. U. npana. The coarse U. australis is, however, much the commonest species of the bush, as is Hie dwarf grasslike U. mpcstns on tiro hill tops. , , . The true Carex has some twenty oi mere representatives. Home are common; some are rare; most are difficult of discrimination. The tall, coarse-growing C. Forsteri will invanbly be found in bush, end cannot he mistaken. Bmuhirly m the swamps GarexXsecla, (he well-known Maorihead and two similar species, G. appressa and ’C virgata with very long, slender, knife-edged seed-stalks, are everywhere common. On Cargill's Cliffs a very coarse large-headed form is to be found winch is known as C. trifida. The creeping sand -edge previously noted (C. purnila) cannot be "confused with any other. Due ot the commonest sedges (C. ternana) is a tall, grassy plant with numerous pendulous cylindrical spikelots each, about an inch to an inch and a-half in length. Urn will be found in any habitually damp spot A very common plant, but easily overlooked on' account cf its diminutive size, and grasslikc appearance, grows on most of our hillsides, notably at \Myare Flat. Bad.lie Hill, and Signal Hill. It is very apl-h termed C. brevitxdmis because its 'seed stalks are seldom much more l.iau an inch long. In strong contrast to llrs is C lueida, it narrow-loafed species with seed’ stalks lengthening in some cases to nine, and ton feel as I have noted at A hare. Flat and on Budding Island, where I got one ’stalk in length. . In bogs bordering tho Kaikorai .‘swamp a very distinct yellowish-green sedge with compact clusters ot pale, sharply taper mg spikolets is still to bo seen, which till recently was believed to be identical with (he European C. flava. Dr I’etne has pointed out to me that this is now generally recognised by the lengthy name of O. oedcri var. calarractae. Here and there round the harbour a lax tussqek-like sedge mav sometimes be seen, which elsewhere in the area we have been examining is known to me only from Brighton, where it is quite uncommon. IK restricted, coastal habitat has earned for it the name of G. lltorosa. On the dampei parts of the top thousand feet of Maungalna occur dense areas of an exceedingly variable sedge known as Gaudiehaudiana, which is very susceptible to attack by a black smut. On the lower slopes and on the lulls from there to Whare Flat a small sedge, C. G’olcnsoi, with a threadlike sced-sta.lk six to twelve inches long bearing a compact cluster of spiklel-s at or near the tip, may bo gathered without difficulty, likewise a somewhat similar but paler and more grassy species (A in versa, which, as a rule, has erect seed-stalks in place of the drooping or procumbent stalks rf the former one. A common laxly-tufted sedge with slender culms which frequently elongate to several feet, and known us C. testacea. is best distinguished from C. lueida. which has tho same habit, by the more closely aggregated spikelots, of which only one is a male spikelet, whereas there may bn one, two, or throe such in the other. In this connection it may be well to state that in all tho above sedges the, very narrow spikelets, or portions of spikolets, are male, and the broader seed-producing spikelets, or portions of spikelets, aro female.

‘.Still another carex, yvith broad, flat, in deeply-grooved leaves met yvith sparingly in Leith Valley is Carex dissita. The culms or flower-steins are smooth, slender, and leafy, and, as with (.'. testaeea, there is seldom more than a single male spikelct. A pink tinted Carex with whitish spikclefs and quite distinct from any other local sedge is reported from Lake Waihola, but I have not searched for it, so cannot say whether it slifl grows there or not Its name is C. Buchanani. At Waipori I found G. psoudo-cyperus, a tall, very distinct looking sedge till then reported only from Otago Heads, whore I have not seen tt , THE GRASSES. Between 40 and 50 native grasses have been collected in tho Dunedin district, while the naturalised grasses now growing beyond the confines of onr cultivated fields number almost as many. The forest grasses have been noted, and the introduced grasses yvo shall ignore "Ihe tallest and most conspicuous grasses are species of snow-grass (Danthonia) and tho toitoi (Arnndo). On Flagstaff and other high hills both the giant tussocks (D. Cunninghamii anil D. Raoulii) arc to bo seen in some quantity while on the yvestern slopes of Flagstaff D. Buchanani var. tenuis is now reported for the first time. Its discovery was made by Dr Petrie, who is recognised as New Zealand’s leading exponent of tho native grasses and sedges. Even commoner species of this genus aro D. somiannnlaris and D. pilosa, the former growing everywhere, tho latter most easily got from Signal Hill. Poas are represented hv the common silver tussock and the bine tussock (I*, colensci). A shore-loving species formerly thought to he Poa lilorosa but uoyv known to bo Poa Aston I, is common at Brighton and at Anderson’s Bay. P. nusilla, P. anceps. and P. Lindsayi are all hillside local species. Fescues have two local representatives—a coarse species from (he sand hills Festuca littoral is and an abundant species on the higher levels, F. novse-zoalandioa (not F. rubra as given in the Field Club Catalogue). The bent grasses (Agrostis and Deyeuxia) have eight representatives —one growing on coastal stations (D. Bil'ardicri) and having broad leaves and a. large feathery flowerstalk. while the others are distributed over the hillsides. Agrostis parvi flora is said to be restricted to the yvestern sioo of Opoho Valley; A. musoosa, a moss-like species, to Maungatua summit; and A, Petriei to .Swampy Hill. Other local species aro A. Dycri, the commonest of all, Deyenxia Forstcri, D. avetioide.s, and D. quadriseta. Trisetum antarelicum is a tall graceful grass common near the entrance to Hooper s Inlet, yvhile the' plume grass Dichclachne crinata and tho wheat grass Agropyrum scab rum, sometimes termed the blue-grass, are exceedingly common in dry stations. Tho holy-grass Hiorochloe redolens is a plentiful, hrc'iid-leaved, sweet-scented grass very common along the seacoast and in damp spots on the bills. High up on Swampy and Maungatua a smaller species, H. Fiv.seri. replaces it The boarded bristle-grass (Echinopogon ovatus) is a grass of the scrub or shade with a pointed or rounded bristly seed-top. Two species of Dcschampsia, one (D. caespitosa) of open but boggy land and the other (D. tenelia) always to found in bush as at Morrison’s Creek or at the head of Leith Saddle, are by no means common. A peculiar but small, worthless grass (Triodia australis) found on the summit of Haungatua and on the western slope of Flagstaff near tho summit is far from easy to find. Much more common is the native sweet-grass, Atropis stricta so plentiful on the Tainui flats and simitar places; while a. widely distributed .grass, ranging from tho sandhills to the middle slopes of Maungatua. is known as Koeleria Kurfzii. An inconspicuous though tall-stemmed grass by no means common now (Aspereila gracilis) is nearly always found near the bush margin: while the native foxtail (Alopocurus geniculatus), already referred (o is rapidly spreading in suitable - swampy localities. Lastly, two relatives of the bush ricc-grass (Mierolama stipoides and, -VI. Dolvnoda) are represented by odd specimens growing in the bush on the Town IBelt <mc* on Signal Hill. The previous articles of this series appeared in our iesnos of March 8. 15, an , April 2. 5. 22, and 50, May i, 12, and 26, and June 10.